* config/rs6000/aix.h (OS_MISSING_POWERPC64): Define.
(OS_MISSING_ALTIVEC): Define.
* config/rs6000/darwin.h (ASM_SPEC): Be generous about supplying
-force_cpusubtype_ALL.
* config/rs6000/rs6000.c (rs6000_override_options): Rearrange
CPU information table; now always set all CPU-specific values.
Also, use Altivec and powerpc64 when chip and OS supports them.
From-SVN: r74820
