This is a reland of commit 7bf94d0336
Changes since revert:
- Update string forwarding table with evacuated objects in mark compact.
- Always mark forward objects in string forwarding table.
Original change's description:
> [heap] Transition/Shortcut strings only during GCs without stack
>
> By limiting transitions of (shared) strings and shortcutting of
> Thin/Cons strings to GC withouts stacks, optimizing compilers can rely on
> the invariant that string maps do not change during a GC, allowing them
> to eliminate map checks and enable more aggressive optimizations.
>
> Change-Id: Ic9c9ed7b04b2ceed369484bf048965c083a9a693
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4030578
> Commit-Queue: Patrick Thier <pthier@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#84347}
Change-Id: I1ab0965ff421635457a66fbe7f178d951afe4402
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4035240
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#84424}
733c76b95c