Replacing Array.Empty with SpecializedCollections.EmptyEnumerable

src/EditorFeatures/Core/Implementation/ReferenceHighlighting/AbstractDocumentHighlightsService.cs

@@ -120,7 +120,7 @@ private bool ShouldConsiderSymbol(ISymbol symbol)
                 return additionalReferenceProvider.GetAdditionalReferencesAsync(document, symbol, cancellationToken);
             }
 
-            return Task.FromResult<IEnumerable<Location>>(Array.Empty<Location>());
+            return Task.FromResult<IEnumerable<Location>>(SpecializedCollections.EmptyEnumerable<Location>());
         }
 
         private async Task<IEnumerable<DocumentHighlights>> CreateSpansAsync(