[MIPS] Re-enable ABI->ISA inference

[Matthew Fortune]

Moore, Catherine <Catherine_Moore@mentor.com> writes:
> > gcc/
> >
> >      * config/mips/mips.h (MIPS_ISA_LEVEL_SPEC): Only infer an ISA
> >      level from an ARCH; do not inject the default.
> >      (MIPS_DEFAULT_ISA_LEVEL_SPEC): New macro split out from
> >      MIPS_ISA_LEVEL_SPEC.
> >      (MIPS_ISA_NAN2008_SPEC): Update comment.
> >      (BASE_DRIVER_SELF_SPECS): Likewise.
> >      * config/mips/elfoabi.h (DRIVER_SELF_SPECS): Add
> >      MIPS_DEFAULT_ISA_LEVEL_SPEC.
> >      * config/mips/mti-elf.h (DRIVER_SELF_SPECS): Likewise.
> >      * config/mips/mti-linux.h (DRIVER_SELF_SPECS): Likewise.
> >      * config/mips/sde.h (DRIVER_SELF_SPECS): Likewise.
> > ---
> 
> This looks OK.
Thanks, committed as r219580.

Matthew