Import from libffi master repository.

Import from libffi master repository.

2017-08-31  Tony Reix  <tony.reix@atos.net>

        * src/powerpc/aix.S (ffi_call_AIX): Add debugging pseudo-op and
        labels for EH.
        (ffi_call_go_AIX): New function.
        (_GLOBAL__F_libffi_src_powerpc_aix): New EH frame.
        * src/powerpc/aix_closure.S (ffi_closure_ASM): Add debugging
        pseudo-op and labels for EH.
        (ffi_go_closure_ASM): New function.
        (_GLOBAL__F_libffi_src_powerpc_aix_closure): New EH frame.
        * src/powrpc/ffi_darwin.c (ffi_call_go): New function.
        (ffi_prep_go_closure): New function.
        (ffi_closure_helper_common): Rename from ffi_closure_helper_DARWIN.
        (ffi_closure_helper_DARWIN): Call ffi_closure_helper_common.
        (ffi_go_closure_helper_DARWIN): Call ffi_closure_helper_common.
        * src/powerpc/ffitarget.h (FFI_GO_CLOSURES): Define.

From-SVN: r253386