MIPS[64]: Port: `[Atomics] Make Atomics.exchange a builtin using TF` and `[Atomics] Make Atomics.compareExchange a builtin using TF`

Port 301c1237 and 82b5c8c9

Implemented exchange and compareExchange atomics.

Bug: 
Change-Id: I11a0d3d608ecf809c7947dd560884c6451dcdb3c
Reviewed-on: https://chromium-review.googlesource.com/649186Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#47846}