Add support for pcnt.df, nlzc.df, nloc.df MSA instructions in mips32 and
mips64 simulator.

Bug: 
Change-Id: I15c2e832c317ff81ce3615b7bd269e039c978e93
Reviewed-on: https://chromium-review.googlesource.com/538654
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#46410}