We're not writing C code, so there's not really much of a reason for us to get warnings and errors from code we haven't written!
Unfortunately older clang compilers don't support this argument, so the bootstrap will fail. We don't actually really need to optimized the C code we compile, however, as currently we're just compiling jemalloc and not much else.
It was broken as tried to copy dylibs which are actually never been built for iOS
