We disabled the `delete` optimization, where `delete` on a fast-mode
object goes back in the transition tree, because that optimization
didn't pay attention to constant field tracking.

This change now does the proper fix, which is to invalidate the
constness and properly deoptimize all code that depends on it.

Drive-by-fix: Handlify the DeleteObjectPropertyFast helper.

Bug: chromium:962588, chromium:963999, v8:9233
Change-Id: I5978c32a48d1635b3ce42dc08b00bb2654baa36a
Cq-Include-Trybots: luci.chromium.try:linux-rel,win7-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617251
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61636}