[libc][NFC] Add a death test API adaptation macro

Fuchsia's zxtest has a slightly different death test definition, and
this macro makes our death test API work on Fuchsia.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D95648

GitOrigin-RevId: c73c23f2a91f5a454d782da9918e2160cfe66087
9 files changed