Merged: [map] Try to in-place transition during map update

When searching for a target map during map update, attempt to
update field representations in-place to the more general
representation, where possible.

Bug: chromium:1143772
No-Try: true
No-Presubmit: true
No-Tree-Checks: true

TBR=leszeks@chromium.org, fgm@chromium.org
(cherry picked from commit 8e3ae62d294818733a0322d8e8abd53d4e410f19)

Change-Id: I659890c2f08c14d1cf94242fb875c19837df2dbb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509599
Reviewed-by: Francis McCabe <fgm@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/branch-heads/8.6@{#44}
Cr-Branched-From: a64aed2333abf49e494d2a5ce24bbd14fff19f60-refs/heads/8.6.395@{#1}
Cr-Branched-From: a626bc036236c9bf92ac7b87dc40c9e538b087e3-refs/heads/master@{#69472}
4 files changed
tree: 89b592cb4624c79792e7ff1bc8ee9a82abfd2b7f
  1. build_overrides/
  2. custom_deps/
  3. docs/
  4. gni/
  5. include/
  6. infra/
  7. samples/
  8. src/
  9. test/
  10. testing/
  11. third_party/
  12. tools/
  13. .clang-format
  14. .clang-tidy
  15. .editorconfig
  16. .flake8
  17. .git-blame-ignore-revs
  18. .gitattributes
  19. .gitignore
  20. .gn
  21. .vpython
  22. .ycm_extra_conf.py
  23. AUTHORS
  24. BUILD.gn
  25. CODE_OF_CONDUCT.md
  26. codereview.settings
  27. COMMON_OWNERS
  28. DEPS
  29. ENG_REVIEW_OWNERS
  30. INFRA_OWNERS
  31. INTL_OWNERS
  32. LICENSE
  33. LICENSE.fdlibm
  34. LICENSE.strongtalk
  35. LICENSE.v8
  36. LICENSE.valgrind
  37. MIPS_OWNERS
  38. OWNERS
  39. PPC_OWNERS
  40. PRESUBMIT.py
  41. README.md
  42. S390_OWNERS
  43. WATCHLISTS
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://v8.dev/docs

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*

Contributing

Please follow the instructions mentioned at v8.dev/docs/contribute.