[clang] Add Clang attribute to ensure that fields are initialized explicitly (PR #102040)

[via cfe-commits]

================
@@ -551,3 +551,14 @@ struct full_of_empty empty_test_2(void) {
   struct full_of_empty e;
   return e; // no-warning
 }
+
+struct with_explicit_field {
+  int x;
+  int y [[clang::requires_explicit_initialization]]; // expected-note {{declared}}
----------------
higher-performance wrote:

Ah sorry I missed these. I did update them, but only in the C++ file. This is in the C file which I completely missed. Fixing, thanks.

https://github.com/llvm/llvm-project/pull/102040