This CL contains new created tests for instructions INS and EXT.

TEST=cctest/test-assembler-mips[64]/Ins,
     cctest/test-assembler-mips[64]/Ext
BUG=

Change-Id: Ie62037ee425a5cba3700c5025608fdada144add5
Reviewed-on: https://chromium-review.googlesource.com/561319
Commit-Queue: Miran Karić <Miran.Karic@imgtec.com>
Reviewed-by: Miran Karić <Miran.Karic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#46468}