cmd/asm, cmd/internal/obj/ppc64: Add ISA 2.05, 2.06 and 2.07 instructions.

cmd/asm, cmd/internal/obj/ppc64: Add ISA 2.05, 2.06 and 2.07 instructions.

This change adds instructions from ISA 2.05, 2.06 and 2.07 that are frequently
used in assembly optimizations for ppc64.

It also fixes two problems:

  * the implementation of RLDICR[CC]/RLDICL[CC] did not consider all possible
  cases for the bit mask.
  * removed two non-existing instructions that were added by mistake in the VMX
  implementation (VORL/VANDL).

Change-Id: Iaef4e5c6a5240c2156c6c0f28ad3bcd8780e9830
Reviewed-on: https://go-review.googlesource.com/36230
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>