StoreTaggedSignedField wasn't clearing the lower bits of a
field when writing a 32-bit Smi

Bug: v8:11420
Change-Id: I543a35001ca8a78490de2d09539b72f52749b198
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2775571
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73546}