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

[via cfe-commits]

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@@ -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]]; // #FIELD_Y
+};
+
+void aggregate() {
+  struct with_explicit_field a; // expected-warning {{field in 'with_explicit_field' is not explicitly initialized, but was marked as requiring explicit initialization}} expected-note@#FIELD_Y {{'y' declared here}}
+  struct with_explicit_field b = {1}; // expected-warning {{field 'y' is not explicitly initialized, but was marked as requiring explicit initialization}} expected-note@#FIELD_Y {{'y' declared here}}
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higher-performance wrote:

Done.

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