Changes since original:
- Updated to use the returned value from CompleteMergeInForeground as
the compilation result, which is important for correctness.
- Added a test to verify the above.
- Moved the merge code into code-serializer.cc so that it can run before
FinalizeDeserialization, which makes it more consistent with
background deserialization.
Original change's description:
> Merge with cached Script after synchronous deserialization
>
> Currently, if a script is deserialized on a background thread and a
> matching Script object is found in the Isolate compilation cache, the
> new content is merged into the existing Script. This CL implements the
> same merging for the much simpler case of deserializing on the main
> thread. I expect speed changes to be minimal, because merging is only
> needed in a small minority of compilations. When needed, it usually
> takes about 10% as long as the corresponding deserialization.
>
> Bug: v8:12808
> Change-Id: Ie7a92bcb3111edf4cdab0eddeb7567979b35f437
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4010100
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#84123}
Bug: v8:12808
Change-Id: I0628a381644e79888cb3ebdd97bda270814d0e9b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4014644
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#84255}
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