Reland "[heap] Refactor Heap::PerformGarbageCollection"

This reverts commit 6fba287c.

Reason for revert: Not the cause.

Original change's description:
> Revert "[heap] Refactor Heap::PerformGarbageCollection"
>
> This reverts commit d0dbee47.
>
> Reason for revert: Breaks MSVC bot (https://cr-buildbucket.appspot.com/build/8880517266974148704)
>
> Original change's description:
> > [heap] Refactor Heap::PerformGarbageCollection
> >
> > This ensures that PerformGarbageCollection runs completely within a
> > LocalHeap safepoint. External prologues and epilogues that may trigger
> > GC and run JS are moved outside.
> >
> > Bug: v8:10315
> >
> > Change-Id: I5c0081f0791ba5d27152c119a2a0d454056656d3
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2190756
> > Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
> > Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> > Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#67736}
>
> TBR=ulan@chromium.org,mlippautz@chromium.org,dinfuehr@chromium.org
>
> Change-Id: I62e62d3f4cd50a3e8f0037902f158baef68cb3b1
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: v8:10315
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2195823
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67739}

TBR=ulan@chromium.org,mlippautz@chromium.org,leszeks@chromium.org,dinfuehr@chromium.org

Bug: v8:10315
Change-Id: I8b9046c51fd43ca48066250085f589f6aa81d5f5

# Reland without changes.

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I8b9046c51fd43ca48066250085f589f6aa81d5f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2196301
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67743}

src/heap/heap.h

@@ -1635,10 +1635,9 @@ class Heap {
   // over all objects.  May cause a GC.
   void MakeHeapIterable();
 
-  // Performs garbage collection
-  // Returns whether there is a chance another major GC could
-  // collect more garbage.
-  bool PerformGarbageCollection(
+  // Performs garbage collection in a safepoint.
+  // Returns the number of freed global handles.
+  size_t PerformGarbageCollection(
       GarbageCollector collector,
       const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags);