[Clang] Remove `IDNS_Ordinary` flag in `IndirectFieldDecl::IdentifierNamespace` (#100525)

There is a `IDNS_Ordinary` flag in
`IndirectFieldDecl::IdentifierNamespace` so that members in nested
anonymous struct/union can be found as ordinary identifiers.

```c
struct S {
  struct { int x; };
  // Previous behaviour: `x` in previous line is found
  // Expected: nothing is found
  int arr[sizeof(x)];
};
```

This PR fixes this issue.

Fixes #31295.

1 files changed, 1 insertions, 2 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index bc5a920..a1f7054 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -879,8 +879,6 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
       return IDNS_Ordinary;
     case Label:
       return IDNS_Label;
-    case IndirectField:
-      return IDNS_Ordinary | IDNS_Member;
 
     case Binding:
     case NonTypeTemplateParm:
@@ -918,6 +916,7 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
       return IDNS_ObjCProtocol;
 
     case Field:
+    case IndirectField:
     case ObjCAtDefsField:
     case ObjCIvar:
       return IDNS_Member;