Fix test failures related to 'counted_by' on 'void *'

Author: rapidsna

clang/test/Sema/attr-counted-by-late-parsed-struct-ptrs.c

@@ -123,7 +123,8 @@ struct on_member_pointer_const_incomplete_ty_ty_pos {
 };
 
 struct on_member_pointer_void_ty_ty_pos {
-  // expected-error@+1{{'counted_by' cannot be applied to a pointer with pointee of unknown size because 'void' is an incomplete type}}
+  // expected-warning@+2{{'counted_by' on a pointer to void is a GNU extension, treated as 'sized_by'}}
+  // expected-note@+1{{use '__sized_by' to suppress this warning}}
   void *__counted_by(count) buf;
   int count;
 };

clang/test/Sema/attr-counted-by-or-null-late-parsed-struct-ptrs.c

@@ -124,7 +124,8 @@ struct on_member_pointer_const_incomplete_ty_ty_pos {
 };
 
 struct on_member_pointer_void_ty_ty_pos {
-  // expected-error@+1{{'counted_by_or_null' cannot be applied to a pointer with pointee of unknown size because 'void' is an incomplete type}}
+  // expected-warning@+2{{'counted_by_or_null' on a pointer to void is a GNU extension, treated as 'sized_by_or_null'}}
+  // expected-note@+1{{use '__sized_by_or_null' to suppress this warning}}
   void *__counted_by_or_null(count) buf;
   int count;
 };