[clang] nolock/noalloc attributes (PR #84983)

[via cfe-commits]

Sirraide wrote:

> Adapted from `test/Sema/initialize-noreturn.c`

Seeing as that test does check that we’re issuing an error for this, and seeing that this seems to be handled in `isFunctionConversion()`, it really just seems like that function is supposed to error if there is a conversion (i.e. if `Changed` is `true` and the `from` and `to` types don’t compare equal).

https://github.com/llvm/llvm-project/pull/84983