Merge pull request #40790 from dotnet/dev/dibarbet/revert_revert_use_index

Revert "Merge pull request #40765 from dibarbet/revert_use_index"

src/EditorFeatures/CSharp/Highlighting/KeywordHighlighters/AsyncAwaitHighlighter.cs

@@ -104,10 +104,10 @@ private static bool TryAddAsyncOrAwaitKeyword(SyntaxToken mod, List<TextSpan> sp
                 if (spans.Count > 0)
                 {
                     var previousToken = mod.GetPreviousToken();
-                    var lastSpan = spans[spans.Count - 1];
+                    var lastSpan = spans[^1];
                     if (lastSpan == previousToken.Span)
                     {
-                        spans[spans.Count - 1] = TextSpan.FromBounds(lastSpan.Start, mod.Span.End);
+                        spans[^1] = TextSpan.FromBounds(lastSpan.Start, mod.Span.End);
                         return true;
                     }
                 }

src/Workspaces/Core/Portable/Microsoft.CodeAnalysis.Workspaces.csproj

@@ -108,6 +108,9 @@
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ImmutableListExtensions.cs">
       <Link>InternalUtilities\ImmutableListExtensions.cs</Link>
     </Compile>
+    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\Index.cs">
+      <Link>InternalUtilities\Index.cs</Link>
+    </Compile>
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ISetExtensions.cs">
       <Link>InternalUtilities\ISetExtensions.cs</Link>
     </Compile>
@@ -141,6 +144,9 @@
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\PlatformInformation.cs">
       <Link>InternalUtilities\PlatformInformation.cs</Link>
     </Compile>
+    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\Range.cs">
+      <Link>InternalUtilities\Range.cs</Link>
+    </Compile>
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ReaderWriterLockSlimExtensions.cs">
       <Link>InternalUtilities\ReaderWriterLockSlimExtensions.cs</Link>
     </Compile>