[clangd] Fix an assertion failure in NamedDecl::getName during the prepareRename

getName method required to be called on a simple-identifier NamedDecl,
otherwise it will trigger an assertion.

Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D153617

Author: hokein

clang-tools-extra/clangd/refactor/Rename.cpp

@@ -332,7 +332,8 @@ const NamedDecl *lookupSiblingWithinEnclosingScope(ASTContext &Ctx,
       return nullptr;
     for (const auto &Child : DS->getDeclGroup())
       if (const auto *ND = dyn_cast<NamedDecl>(Child))
-        if (ND != &RenamedDecl && ND->getName() == Name)
+        if (ND != &RenamedDecl && ND->getDeclName().isIdentifier() &&
+            ND->getName() == Name)
           return ND;
     return nullptr;
   };

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

@@ -1129,6 +1129,15 @@ TEST(RenameTest, Renameable) {
         using ns::^foo;
       )cpp",
        "there are multiple symbols at the given location", !HeaderFile},
+
+      {R"cpp(
+        void test() {
+          // no crash
+          using namespace std;
+          int [[V^ar]];
+        }
+      )cpp",
+        nullptr, !HeaderFile},
   };
 
   for (const auto& Case : Cases) {