For keyed stores we recompute handlers based on the receiver maps
we have seen. This is done so that we can transition to the most generic
elements kind we have seen so far. When we recompute this handlers we
get a new prototype validity cell and ignore the existing cell. This
leads to incorrect behaviour if the cell was invalid. Recomputing the
handler may be extra work which is not worth doing at this point. So
we just reuse the existing validity cell and let the IC recompute the
handler if we see the map again.

Bug: chromium:1053939
Change-Id: Ifc891d70f5a4b8b774238e12fb40e29b4d174e37
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2122032
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66963}