[clangd] Report reference to UsingType's target decl at the correct location (llvm#186310)

Fixes clangd/clangd#2617

Author: HighCommander4

clang-tools-extra/clangd/FindTarget.cpp

@@ -845,14 +845,14 @@ refInTypeLoc(TypeLoc L, const HeuristicResolver *Resolver) {
 
     void VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc L) {
       Refs.push_back(ReferenceLoc{L.getQualifierLoc(),
-                                  L.getLocalSourceRange().getBegin(),
+                                  L.getNameLoc(),
                                   /*IsDecl=*/false,
                                   {L.getDecl()}});
     }
 
     void VisitUsingTypeLoc(UsingTypeLoc L) {
       Refs.push_back(ReferenceLoc{L.getQualifierLoc(),
-                                  L.getLocalSourceRange().getBegin(),
+                                  L.getNameLoc(),
                                   /*IsDecl=*/false,
                                   {L.getDecl()}});
     }

clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp

@@ -1100,7 +1100,13 @@ sizeof...($TemplateParameter[[Elements]]);
         struct $Class_def[[Inner]] {};
       };
       using $Typedef_decl[[Alias]] = void ($Class[[Outer]]::$Class[[Inner]]:: *)();
-    )cpp"};
+    )cpp",
+      // Forwarded typedef
+      R"cpp(
+      using $Primitive_decl[[MyInt]] = int;
+      namespace $Namespace_decl[[N]] { using ::MyInt; }
+      using $Primitive_decl[[X]] = $Namespace[[N]]::$Primitive[[MyInt]];
+      )cpp"};
   for (const auto &TestCase : TestCases)
     // Mask off scope modifiers to keep the tests manageable.
     // They're tested separately.