[clang] [clang-tools-extra] [clang] Skip suggesting unqualified members in explicit-object member functions (PR #153760)

[Mythreya Kuricheti via cfe-commits]

================
@@ -1428,6 +1428,16 @@ void ResultBuilder::AddResult(Result R, DeclContext *CurContext,
 
   AdjustResultPriorityForDecl(R);
 
+  if (isa<FieldDecl>(R.Declaration)) {
+    // If result is a member in the context of an explicit-object member
+    // function, drop it because it must be accessed through the object
+    // parameter
+    if (auto *MethodDecl = dyn_cast<CXXMethodDecl>(CurContext);
----------------
MythreyaK wrote:

How do we ensure that explicit object methods still participate in overload resolution, since the `HasObjectTypeQualifiers` is `false` [here](https://searchfox.org/llvm/rev/a293573c4e3e43f9f6279f075c3262ea5dc17086/clang/lib/Sema/SemaCodeComplete.cpp#1431)? 

Example, his does not suggest `memberFnB`

```cpp
struct A {
  int member {};
  int memberFnA(int a);
  int memberFnB(this A const& self, float b);

  void foo(this const A& self) {
    self.mem^ // suggests only 'member'
    self.memberFnA(1); // correctly diagnosed by clangd
  }
};
```

Should `HasObjectTypeQualifiers` be true for these? 

https://github.com/llvm/llvm-project/pull/153760