- Add %BaselineOsr to manually trigger OSR to Baseline.
- Add flags to %GetOptimizationStatus to check if the topmost frame is
an Interpreter/Baseline frame.
- Add mjsunit test.

Bug: v8:11420
Change-Id: Id80421ad97ee719a67ef299cc700da9c44f23bae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2814567
Auto-Submit: Patrick Thier <pthier@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73937}