This change adds a flag v8_enable_fast_torque, which follows the pattern
of v8_enable_fast_mksnapshot and can improve build times by running an
optimized Torque compiler during debug builds. On my machine, this
change improves rebuild time after changing a .tq file by about 7
seconds.

Change-Id: I7c91d1059c614fe34eefe7ee8c3cba7c931d5a50
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1612160
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61556}