Edit: Wow, as a result of your other comment about GCC I was surprised to learn that none of the Z80 compilers I could find appear to support this sort of thing. It looks like there was (previously?) an effort to put together a Z80 backend for LLVM, but my search results didn't look promising.
Yeah, it's a newer concept for the compiler space (it relies on having a lot of compiler host memory, more than you might think), and I'm not sure that the more niche compilers have had time to get this feature yet.
Edit: Wow, as a result of your other comment about GCC I was surprised to learn that none of the Z80 compilers I could find appear to support this sort of thing. It looks like there was (previously?) an effort to put together a Z80 backend for LLVM, but my search results didn't look promising.