This CL makes more assumptions in the fast-api-call mjsunit test
explicit and specifies --deopt-every-n-times=0 for it, as it relies
on particular optimization/deoptimization sequences. It also fixes an
inconsistency between the fast/slow path results.

Bug: v8:11620
Change-Id: I385949a04534cd1658236878875efa6622936bc5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2817607Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73905}