since i've yet to dig into if any libgcc symbols ever get invoked, heres versions of the RC for mac built using gcc5 and apple clang respectively (in addition to the other one i've already provided that has a gcc6 libgcc dylib that seems to spuriously leak through)

https://wellposed-carter-files.s3.amazonaws.com/opensource/ghc/releasebuild-unofficial/vanilla-clang-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz

shasum -a512 vanilla-clang-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz
9105b097bb8036d6a77fc7bb87bcb0efff4ac7136232ac7ce109664ecae6e0e6757904f4a80de9120813530b979e7d90a36b4b28a1ef7bb9c371ab10a346c9dc  vanilla-clang-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz

http://wellposed-carter-files.s3.amazonaws.com/opensource/ghc/releasebuild-unofficial/vanilla-gcc5-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz

shasum -a512 vanilla-gcc5-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz
43bb84fe73ac9e450d73a877022ba2ca514a08f69c18cac7367ed7038e9f7371b21cdaeef635aee345f9ba001a2fb5b527975e790f1b8d1c6f91bdf231e05090  vanilla-gcc5-ghc-8.0.0.20160421-x86_64-apple-darwin.tar.xz

enjoy!
-Carter