This CL fixes a segfault when Wasm tried to generate a builtin call
from background compilation job when the Isolate was already teared
down by the main thread.

Drive-by: Use CallBuiltin in RegExpMacroAssemblerARM64.

Bug: v8:11527, chromium:1195552
Change-Id: I8048ffcb212bda4d19d07b5ec6b487d6fb16b30d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2811739
Auto-Submit: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73850}