[api] Fix SuppressMicrotaskExecutionScope constructor

The overload taking a `MicrotaskQueue*` was introduced in
cce33f37 but never actually implemented.

This aligns the constructor signature to actually work, and
aligns it with e.g. `MicrotasksScope`. The previous signature
without an `Isolate*` argument would not work, because there’s
no pointer back from a MicrotaskQueue to the Isolate.

Refs: https://chromium-review.googlesource.com/c/v8/v8/+/1414950
Bug: v8:8124
Change-Id: I5dbaabef54c8de2b48f6172808825a186971524d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1879901Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64584}

include/v8.h

@@ -8045,8 +8045,8 @@ class V8_EXPORT Isolate {
    */
   class V8_EXPORT SuppressMicrotaskExecutionScope {
    public:
-    explicit SuppressMicrotaskExecutionScope(Isolate* isolate);
-    explicit SuppressMicrotaskExecutionScope(MicrotaskQueue* microtask_queue);
+    explicit SuppressMicrotaskExecutionScope(
+        Isolate* isolate, MicrotaskQueue* microtask_queue = nullptr);
     ~SuppressMicrotaskExecutionScope();
 
     // Prevent copying of Scope objects.

src/api/api.cc

@@ -8408,9 +8408,11 @@ Isolate::AllowJavascriptExecutionScope::~AllowJavascriptExecutionScope() {
 }
 
 Isolate::SuppressMicrotaskExecutionScope::SuppressMicrotaskExecutionScope(
-    Isolate* isolate)
+    Isolate* isolate, MicrotaskQueue* microtask_queue)
     : isolate_(reinterpret_cast<i::Isolate*>(isolate)),
-      microtask_queue_(isolate_->default_microtask_queue()) {
+      microtask_queue_(microtask_queue
+                           ? static_cast<i::MicrotaskQueue*>(microtask_queue)
+                           : isolate_->default_microtask_queue()) {
   isolate_->thread_local_top()->IncrementCallDepth(this);
   microtask_queue_->IncrementMicrotasksSuppressions();
 }