PowerPC: Support for Additional Performance Monitor Counters (RFC02666)

opcodes/
        * ppc-opc.c (powerpc_opcodes): Add mtummcrae, mtummcr2e,
        mtmmcr2e, mtmmcrae, mtmmcr1e, mtmmcr3e, mtupmc7, mtupmc8,
        mtpmc7, mtpmc8, mfummcrae, mfmmcrae, mfummcr1e, mfmmcr1e,
        mfummcr2e, mfmmcr2e, mfummcr3e, mfmmcr3e, mfupmc7, mfpmc7,
        mfupmc8, mfpmc8.

gas/
        * testsuite/gas/ppc/future.s: New test.
        * testsuite/gas/ppc/future.d: Likewise.