[compiler-rt] [compiler-rt] [Darwin] libFuzzer tests should use darwin_filter_host_archs (PR #160578)

[Paddy McDonald via llvm-commits]

padriff wrote:

You may want to split this into two commits - the first with just the semantic change, the second with the clang-format changes to make it easier to understand the exact diffs

https://github.com/llvm/llvm-project/pull/160578