Avoiding handles in tight loops and setup code improves performance
and reduces code size.

This CL also makes more non-allocating mode more explicit by adding
more DisallowGarbageCollection scopes.

Change-Id: I95b5b1a29204c27a23c42ccd67fff150b3fa4a3e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3460740Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79142}