Revert "[wasm][gc] Use SetPermissions to discard pages"

This reverts commit cc71d5ca52159ff1a7f5c736df380f91d4605a88.

Reason for revert: gc-stress failures, e.g.

Original change's description:
> [wasm][gc] Use SetPermissions to discard pages
> On 32bit windows, DiscardSystemPages fails sometimes (see bug). We don't
> have a reproducer, so this is a purely speculative fix.
> {SetPermissions} has some platform-specific logic to also discard the
> pages. Specifially, on windows it uses {VirtualFree} instead of
> {DiscardVirtualMemory}.
> {SetPermissions} is also semantically stronger, since it forbids any
> further access to the pages.
> R=​
> Bug: v8:8217, chromium:960707
> Change-Id: I8b3325264c86aff8d6e7c6b01c22ae410e87faf4
> Reviewed-on:
> Reviewed-by: Michael Starzinger <>
> Commit-Queue: Clemens Hammacher <>
> Cr-Commit-Position: refs/heads/master@{#61321},

Change-Id: Ib2d534a6906ea5d390d08943ea71e1f8799278e8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8217, chromium:960707
Reviewed-by: Clemens Hammacher <>
Commit-Queue: Clemens Hammacher <>
Cr-Commit-Position: refs/heads/master@{#61324}
1 file changed
tree: 80e2c2e86322462a2e11f08aa1cae344a347499f
  1. .clang-format
  2. .clang-tidy
  3. .editorconfig
  4. .git-blame-ignore-revs
  5. .gitattributes
  6. .gitignore
  7. .gn
  8. .vpython
  13. ChangeLog
  14. DEPS
  16. LICENSE.fdlibm
  17. LICENSE.strongtalk
  18. LICENSE.v8
  19. LICENSE.valgrind
  20. OWNERS
  24. benchmarks/
  25. build_overrides/
  26. codereview.settings
  27. custom_deps/
  28. docs/
  29. gni/
  30. include/
  31. infra/
  32. samples/
  33. snapshot_toolchain.gni
  34. src/
  35. test/
  36. testing/
  37. third_party/
  38. tools/

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.

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