Cast to int32_t after checking the range.

Bug: v8:10921

Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng,v8_linux64_asan_rel_ng,v8_linux64_tsan_isolates_rel_ng,v8_linux64_msan_rel_ng,v8_linux64_tsan_rel_ng,v8_mac64_asan_rel_ng,v8_win64_asan_rel_ng,v8_linux64_gcc_compile_dbg,v8_linux_gcc_compile_rel,v8_linux_gcc_rel_ng,v8_linux64_gc_stress_custom_snapshot_dbg_ng,v8_linux_arm64_gc_stress_dbg_ng,v8_linux_gc_stress_dbg_ng,v8_mac64_gc_stress_dbg_ng;luci.chromium.try:linux_chromium_ubsan_rel_ng

Change-Id: I9c3631a2f3aa34bc9c87a6f40a2888b38832978c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414622
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70008}