deps: V8: use ATOMIC_VAR_INIT instead of std::atomic_init

`std::atomic_init<size_t>` is not implemented in all platforms.

* pragma to ignore `-Wbraced-scalar-init`

Backport-PR-URL: #28005
PR-URL: #27375
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

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.8',
+    'v8_embedder_string': '-node.9',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/src/wasm/module-compiler.cc

@@ -131,7 +131,14 @@ class CompilationUnitQueues {
       queues_[task_id].next_steal_task_id_ = next_task_id(task_id);
     }
     for (auto& atomic_counter : num_units_) {
-      std::atomic_init(&atomic_counter, size_t{0});
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wbraced-scalar-init"
+#endif
+      atomic_counter = ATOMIC_VAR_INIT(0);
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
     }
   }