Add a test for using with trailing newline

I couldn't find a test like this, but I've been debugging an issue in this
scenario.

test/Microsoft.AspNetCore.Razor.Evolution.Test/Legacy/CSharpBlockTest.cs

@@ -465,6 +465,16 @@ while(true);", BlockType.Statement, SpanKind.Code, acceptedCharacters: AcceptedC
                                    .Accepts(AcceptedCharacters.NonWhiteSpace | AcceptedCharacters.WhiteSpace)));
         }
 
+        [Fact]
+        public void ParseBlockCapturesNewlineAfterUsing()
+        {
+            ParseBlockTest($"using Foo{Environment.NewLine}",
+                           new DirectiveBlock(
+                               Factory.Code($"using Foo{Environment.NewLine}")
+                                   .AsNamespaceImport(" Foo")
+                                   .Accepts(AcceptedCharacters.NonWhiteSpace | AcceptedCharacters.WhiteSpace)));
+        }
+
         [Fact]
         public void ParseBlockParsesNamespaceAliasWithSemicolonForUsingKeywordIfIsInValidFormat()
         {