deps: V8: cherry-pick 0188634

Original commit message:

    [ptr-compr][ubsan] Use [Read/Write]UnalignedValue for unaligned fields

    When pointer compression is enabled the [u]intptr_t and double fields are
    only kTaggedSize aligned so in order to avoid undefined behavior in C++ code
    we have to access these values in an unaligned pointer friendly way although
    both x64 and arm64 architectures (where pointer compression is supported)
    allow unaligned access.

    These changes will be removed once v8:8875 is fixed and all the
    kSystemPointerSize fields are properly aligned.

    Bug: v8:7703
    Change-Id: I4df477cbdeab806303bb4f675d52b61c06342c8e
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1528996
    Commit-Queue: Igor Sheludko <ishell@chromium.org>
    Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    Reviewed-by: Jakob Gruber <jgruber@chromium.org>
    Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#60321}

Refs: https://github.com/v8/v8/commit/0188634ee523aef39ba71732b1ab9d422f449825

PR-URL: https://github.com/nodejs/node/pull/27013
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 1 insertions, 2 deletions

diff --git a/deps/v8/src/objects/bigint.h b/deps/v8/src/objects/bigint.h
index ae1ffe6866..4ddb57a5b2 100644
--- a/deps/v8/src/objects/bigint.h
+++ b/deps/v8/src/objects/bigint.h
@@ -87,8 +87,7 @@ class BigIntBase : public HeapObject {
 
   inline digit_t digit(int n) const {
     SLOW_DCHECK(0 <= n && n < length());
-    Address address = FIELD_ADDR(*this, kDigitsOffset + n * kDigitSize);
-    return *reinterpret_cast<digit_t*>(address);
+    return READ_UINTPTR_FIELD(*this, kDigitsOffset + n * kDigitSize);
   }
 
   bool is_zero() const { return length() == 0; }