Fix highlighting of identifiers declared in LINQ join clauses

ICSharpCode.Decompiler/CSharp/Transforms/IntroduceQueryExpressions.cs

@@ -258,12 +258,14 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 							query.Clauses.Add(MakeFromClause(element1, source1.Detach()));
 							QueryJoinClause joinClause = new QueryJoinClause();
 							joinClause.JoinIdentifier = element2.Name;    // join elementName2
+							joinClause.JoinIdentifierToken.CopyAnnotationsFrom(element2);
 							joinClause.InExpression = source2.Detach();  // in source2
 							joinClause.OnExpression = key1.Detach();     // on key1
 							joinClause.EqualsExpression = key2.Detach(); // equals key2
 							if (mre.MemberName == "GroupJoin")
 							{
 								joinClause.IntoIdentifier = p2.Name; // into p2.Name
+								joinClause.IntoIdentifierToken.CopyAnnotationsFrom(p2);
 							}
 							joinClause.AddAnnotation(new QueryJoinClauseAnnotation(outerLambda.Annotation<IL.ILFunction>(), innerLambda.Annotation<IL.ILFunction>()));
 							query.Clauses.Add(joinClause);

ICSharpCode.Decompiler/Output/TextTokenWriter.cs

@@ -85,7 +85,7 @@ namespace ICSharpCode.Decompiler
 					return;
 			}
 
-			var localDefinition = GetCurrentLocalDefinition();
+			var localDefinition = GetCurrentLocalDefinition(identifier);
 			if (localDefinition != null)
 			{
 				output.WriteLocalReference(name, localDefinition, isDefinition: true);
@@ -169,7 +169,7 @@ namespace ICSharpCode.Decompiler
 			return null;
 		}
 
-		object GetCurrentLocalDefinition()
+		object GetCurrentLocalDefinition(Identifier id)
 		{
 			AstNode node = nodeStack.Peek();
 			if (node is Identifier && node.Parent != null)
@@ -182,6 +182,13 @@ namespace ICSharpCode.Decompiler
 					return variable;
 			}
 
+			if (id.Role == QueryJoinClause.IntoIdentifierRole || id.Role == QueryJoinClause.JoinIdentifierRole)
+			{
+				var variable = id.Annotation<ILVariableResolveResult>()?.Variable;
+				if (variable != null)
+					return variable;
+			}
+
 			if (node is QueryLetClause)
 			{
 				var variable = node.Annotation<CSharp.Transforms.LetIdentifierAnnotation>();