deps: V8: revert e3cddbedb205

simdutf's `atomic_binary_to_base64` requires `std::atomic_ref`.
`std::atomic_ref` is only available in LLVM 19, which is only available
in Xcode 16.3, which is only available on macOS 15.

This also includes a revert of dfd7a5a3c9f57, which modifed the affected
lines.

Refs: llvm/llvm-project#76647
Refs: v8/v8@e3cddbe
PR-URL: nodejs#58064
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>

Author: targos

common.gypi

@@ -38,7 +38,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.5',
+    'v8_embedder_string': '-node.7',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/BUILD.bazel

@@ -4401,12 +4401,6 @@ cc_library(
   name = "simdutf",
   srcs = ["third_party/simdutf/simdutf.cpp"],
   hdrs = ["third_party/simdutf/simdutf.h"],
-  copts = select({
-        "@v8//bazel/config:is_clang": ["-std=c++20"],
-        "@v8//bazel/config:is_gcc": ["-std=gnu++2a"],
-        "@v8//bazel/config:is_windows": ["/std:c++20"],
-        "//conditions:default": [],
-    }),
 )
 
 v8_library(

deps/v8/src/builtins/builtins-typed-array.cc

@@ -832,16 +832,11 @@ BUILTIN(Uint8ArrayPrototypeToBase64) {
     //    is false.
     // 11. Return CodePointsToString(outAscii).
 
-    size_t simd_result_size;
-    if (uint8array->buffer()->is_shared()) {
-      simd_result_size = simdutf::atomic_binary_to_base64(
-          std::bit_cast<const char*>(uint8array->DataPtr()), length,
-          reinterpret_cast<char*>(output->GetChars(no_gc)), alphabet);
-    } else {
-      simd_result_size = simdutf::binary_to_base64(
-          std::bit_cast<const char*>(uint8array->DataPtr()), length,
-          reinterpret_cast<char*>(output->GetChars(no_gc)), alphabet);
-    }
+    // TODO(rezvan): Make sure to add a path for SharedArrayBuffers when
+    // simdutf library got updated. Also, add a test for it.
+    size_t simd_result_size = simdutf::binary_to_base64(
+        std::bit_cast<const char*>(uint8array->GetBuffer()->backing_store()),
+        length, reinterpret_cast<char*>(output->GetChars(no_gc)), alphabet);
     DCHECK_EQ(simd_result_size, output_length);
     USE(simd_result_size);
   }
@@ -1068,6 +1063,9 @@ BUILTIN(Uint8ArrayPrototypeToHex) {
     return *isolate->factory()->empty_string();
   }
 
+  const char* bytes =
+      std::bit_cast<const char*>(uint8array->GetBuffer()->backing_store());
+
   //   4. Let out be the empty String.
   DirectHandle<SeqOneByteString> output;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
@@ -1078,8 +1076,8 @@ BUILTIN(Uint8ArrayPrototypeToHex) {
   //    b. Set hex to StringPad(hex, 2, "0", start).
   //    c. Set out to the string-concatenation of out and hex.
   //  6. Return out.
-  return Uint8ArrayToHex(std::bit_cast<const char*>(uint8array->DataPtr()),
-                         length, uint8array->buffer()->is_shared(), output);
+  return Uint8ArrayToHex(bytes, length, uint8array->buffer()->is_shared(),
+                         output);
 }
 
 }  // namespace internal