Test started failing after commit `[Liftoff] Remove Get{Unary,Binary}OpTargetRegister`.
Optimization shouldn't be done if dst == rhs in i32_set_cond instruction.
This CL fixes the issue.

Change-Id: I67cd1ca4692fcf69202ef25f7aa58756a5ddddca
Reviewed-on: https://chromium-review.googlesource.com/952963Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#51806}