Smi handler in LoadIC is decoded to IntPtrT and result in
sign-extending Smi's value when pointer compression is enabled. This
CL avoid this sign-extension by decoding the Smi to Int32T.

Change-Id: I3ddd6dcec8654d6c13d472a077a55698359d126a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3740481
Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81525}