This is a reland of a6b95a6a

In addition to UBSan, also ASAN needs optimizations.
So this CL doesn't disable optimizations for all sanitizer builds.

Original change's description:
> Reland "[build] disable C++ optimization for mksnapshot code."
>
> This is a reland of cee2f772
>
> Original change's description:
> > [build] disable C++ optimization for mksnapshot code.
> >
> > By disabling C++ optimizations for code that's only run in mksnapshot,
> > that is, CSA and Torque-generated code, we can save compile time.
> > I observed up to 2x improvements of compile time for some files,
> > while the mksnapshot time did not increase significantly.
> >
> > Bug: v8:7629
> > Change-Id: I96be2966611b2471b68023e0dd9e351d94f0013c
> > Reviewed-on: https://chromium-review.googlesource.com/c/1460941
> > Reviewed-by: Yang Guo <yangguo@chromium.org>
> > Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#59585}
>
> Bug: v8:7629
> Change-Id: I8330f93173ab3d7b400e15ea4935bbe8256b250f
> Reviewed-on: https://chromium-review.googlesource.com/c/1473292
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59606}

Bug: v8:7629
Change-Id: I42175c472d8e41345573df81645dfe3accc9d8c4
Reviewed-on: https://chromium-review.googlesource.com/c/1475396Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59632}