[clang] [Clang] Add __builtin_counted_by_ref builtin (PR #114495)

[via cfe-commits]

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@@ -13,7 +13,10 @@ void init(void * __attribute__((pass_dynamic_object_size(0))));
 // CHECK-LABEL: define dso_local void @_ZN3foo3barC1Ev(
 // CHECK-SAME: ptr noundef nonnull align 4 dereferenceable(1) [[THIS:%.*]]) unnamed_addr #[[ATTR0:[0-9]+]] align 2 {
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    tail call void @_Z4initPvU25pass_dynamic_object_size0(ptr noundef nonnull align 4 dereferenceable(1) [[THIS]], i64 noundef -1) #[[ATTR2:[0-9]+]]
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Sirraide wrote:

> different behaviour depending on optimisation levels

As in, Clang emits different IR before it even gets to the optimiser.

https://github.com/llvm/llvm-project/pull/114495