[Clang] precommit test

[nickdesaulniers]

Summary

Add test case demonstrating issue.

Link: https://github.com/llvm/llvm-project/issues/62789

[erichkeane]

We don't typically do this in teh FE tests, we typically just commit the whole test in teh patch that fixes it.

[nickdesaulniers]

Merged into D150892

clang/test/CodeGen/object-size.c

void test31(void) {
 
   // CHECK: call i64 @llvm.objectsize.i64.p0(ptr %{{.*}}, i1 false, i1 true, i1
   gi = OBJECT_SIZE_BUILTIN(&ds0[9].snd[0], 1);
 
   // CHECK: call i64 @llvm.objectsize.i64.p0(ptr %{{.*}}, i1 false, i1 true, i1
   gi = OBJECT_SIZE_BUILTIN(&dsv[9].snd[0], 1);
 }
 
+// CHECK-LABEL: @test32
+static struct DynStructVar D = {
+  .fst = {},
+  .snd = { 0, 1, 2, },
+};
+unsigned long test32(void) {
+  // FIXME: GCC returns the sizeof the base type, plus the number of bytes from
+  // members of the initializer of the flexible array: 19.
+  // CHECK: ret i64 16
+  return __builtin_object_size(&D, 1);
+}
+
 // CHECK-LABEL: @PR30346
 void PR30346(void) {
   struct sa_family_t {};
   struct sockaddr {
     struct sa_family_t sa_family;
     char sa_data[14];
   };