Pull up following revision(s) (requested by mrg in ticket #757):

external/gpl3/gcc.old/lib/libstdc++-v3/arch/powerpc/gstdint.h: revision 1.7
external/gpl3/gcc.old/usr.bin/gcc/arch/powerpc/configargs.h: revision 1.8
external/gpl3/gcc.old/usr.bin/gcc/arch/powerpc/defs.mk: revision 1.7
external/gpl3/gcc.old/usr.bin/gcc/arch/powerpc/gtyp-input.list: revision 1.6
external/gpl3/gcc.old/lib/libstdc++-v3/arch/powerpc/c++config.h: revision 1.8
external/gpl3/gcc.old/usr.bin/gcc/arch/powerpc/tm.h: revision 1.6
external/gpl3/gcc.old/dist/gcc/config.gcc: revision 1.9
(with gcc.old -> gcc)

apply the changes from GCC 6 / powerpc and netbsd-stdint.h
to make <stdatomic.h> work.

(martin)