This is a three-state field now: kTrapHandler, kExplicitBoundsChecks,
kNoBoundsChecks. It is set once based on the flags
(--wasm-bounds-checks and --wasm-enforce-bounds-checks) and depending on
whether the signal handler for wasm trap handling was installed. All
compilation then only uses the field value, and does not need to check
any flags any more.

R=ahaas@chromium.org

Bug: v8:11926
Change-Id: I2c0eb5ecb742ee65d1c10e4dceff7204119dab7c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2996191
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75558}