This changes debug builds [1] to compile src/compiler sources twice:

1. with optimizations, used in mksnapshot to improve performance.
2. without optimizations, linked into d8 and v8 libraries.

While this adds ~200 compilation targets, these can be built in parallel
and should not add much time overall.

This brings mksnapshot runtime back down to 11 seconds on my machine.

[1] The full condition is:
    is_debug && !v8_optimized_debug && v8_enable_fast_mksnapshot

Cq-Include-Trybots: luci.chromium.try:android_arm64_dbg_recipe
Cq-Include-Trybots: luci.chromium.try:fuchsia_x64
Bug: v8:8767
Change-Id: Iac57bf8331395d9eda9be5d192e8eeeded182ae6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1532335
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60713}