Xori instruction can only have unisgned 16-bit immediates for right input,
as such it is not suitable for bit negation on mips.

TEST=unittests/InstructionSecetorTest.Word(32|64)XorMinusOneWithParameter
BUG=

Review URL: https://codereview.chromium.org/1485833003

Cr-Commit-Position: refs/heads/master@{#32478}