[clang] Thread Safety Analysis: Fix implicit member access in attributes (PR #194457)

[Aaron Puchert via cfe-commits]

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@@ -169,10 +169,10 @@ struct TestingMoreComplexAttributes {
 } more_complex_atttributes;
 
 void more_complex_attributes() {
-    more_complex_atttributes.a = true; // expected-warning{{writing variable 'a' requires holding mutex 'lock' exclusively}}
-    more_complex_atttributes.b = true; // expected-warning{{writing variable 'b' requires holding mutex 'strct.lock' exclusively}}
-    *more_complex_atttributes.ptr_a = true; // expected-warning{{writing the value pointed to by 'ptr_a' requires holding mutex 'lock' exclusively}}
-    *more_complex_atttributes.ptr_b = true; // expected-warning{{writing the value pointed to by 'ptr_b' requires holding mutex 'strct.lock' exclusively}}
+    more_complex_atttributes.a = true; // expected-warning{{writing variable 'a' requires holding mutex 'more_complex_atttributes..lock' exclusively}}
+    more_complex_atttributes.b = true; // expected-warning{{writing variable 'b' requires holding mutex 'more_complex_atttributes..strct.lock' exclusively}}
+    *more_complex_atttributes.ptr_a = true; // expected-warning{{writing the value pointed to by 'ptr_a' requires holding mutex 'more_complex_atttributes..lock' exclusively}}
+    *more_complex_atttributes.ptr_b = true; // expected-warning{{writing the value pointed to by 'ptr_b' requires holding mutex 'more_complex_atttributes..strct.lock' exclusively}}
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aaronpuchert wrote:

We probably shouldn't write `..`, but either `.<anonymous union>.` or `.`. There must be some way of properly printing anonymous unions because other diagnostics print them right.

https://github.com/llvm/llvm-project/pull/194457