Fix build break

src/Features/LanguageServer/Protocol/CustomProtocol/FindUsagesLSPContext.cs

@@ -17,6 +17,7 @@
 using Microsoft.CodeAnalysis.FindSymbols;
 using Microsoft.CodeAnalysis.FindSymbols.Finders;
 using Microsoft.CodeAnalysis.FindUsages;
+using Microsoft.CodeAnalysis.MetadataAsSource;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 using Microsoft.VisualStudio.Text.Adornments;

src/Features/LanguageServer/Protocol/Handler/References/FindAllReferencesHandler.cs

@@ -13,6 +13,7 @@
 using Microsoft.CodeAnalysis.Editor.FindUsages;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.LanguageServer.CustomProtocol;
+using Microsoft.CodeAnalysis.MetadataAsSource;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 using LSP = Microsoft.VisualStudio.LanguageServer.Protocol;