Lazily initialize annotations for intermediate nodes.

#1390

src/Microsoft.AspNetCore.Razor.Language/Intermediate/AddTagHelperHtmlAttributeIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class AddTagHelperHtmlAttributeIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/CSharpCodeAttributeValueIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class CSharpCodeAttributeValueIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/CSharpExpressionAttributeValueIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class CSharpExpressionAttributeValueIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/CreateTagHelperIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class CreateTagHelperIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/DeclareTagHelperFieldsIntermediateNode.cs

@@ -9,8 +9,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class DeclareTagHelperFieldsIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/DirectiveTokenIntermediateNode.cs

@@ -6,8 +6,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class DirectiveTokenIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/HtmlAttributeIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class HtmlAttributeIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/HtmlAttributeValueIntermediateNode.cs

@@ -9,8 +9,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class HtmlAttributeValueIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/HtmlContentIntermediateNode.cs

@@ -9,8 +9,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class HtmlContentIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/IntermediateToken.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class IntermediateToken : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/SetTagHelperPropertyIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class SetTagHelperPropertyIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/TagHelperBodyIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class TagHelperBodyIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {

src/Microsoft.AspNetCore.Razor.Language/Intermediate/UsingDirectiveIntermediateNode.cs

@@ -8,8 +8,20 @@ namespace Microsoft.AspNetCore.Razor.Language.Intermediate
     public sealed class UsingDirectiveIntermediateNode : IntermediateNode
     {
         private RazorDiagnosticCollection _diagnostics;
+        private ItemCollection _annotations;
 
-        public override ItemCollection Annotations => ReadOnlyItemCollection.Empty;
+        public override ItemCollection Annotations
+        {
+            get
+            {
+                if (_annotations == null)
+                {
+                    _annotations = new DefaultItemCollection();
+                }
+
+                return _annotations;
+            }
+        }
 
         public override RazorDiagnosticCollection Diagnostics
         {