All conversions, reinterpretations, promotions and demotions are
implemented in Liftoff on MIPS.

Bug: v8:6600
Change-Id: I8920aea1cabdb59676c2c03fbb6de6156ebf0a62
Reviewed-on: https://chromium-review.googlesource.com/983554Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#52277}