[heap,iwyu] More cleanup

The following are ready for iwyu:
- src/heap/mark-compact.h
- src/heap/objects-visiting.h

Bug: v8:7490
Change-Id: I4cb9b1146586adcef8c0e0cf187ca363fe6e9a8d
Reviewed-on: https://chromium-review.googlesource.com/1154970Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54788}

src/heap/mark-compact-inl.h

@@ -578,6 +578,8 @@ typename LiveObjectRange<mode>::iterator LiveObjectRange<mode>::end() {
   return iterator(chunk_, bitmap_, end_);
 }
 
+Isolate* MarkCompactCollectorBase::isolate() { return heap()->isolate(); }
+
 }  // namespace internal
 }  // namespace v8
 

src/heap/mark-compact.h

@@ -257,7 +257,7 @@ class MarkCompactCollectorBase {
   virtual void CollectGarbage() = 0;
 
   inline Heap* heap() const { return heap_; }
-  inline Isolate* isolate() { return heap()->isolate(); }
+  inline Isolate* isolate();
 
  protected:
   static const int kMainThread = 0;

tools/generate-header-include-checks.py

@@ -48,8 +48,6 @@ AUTO_EXCLUDE = [
   'src/elements-inl.h',
   'src/field-type.h',
   'src/heap/incremental-marking.h',
-  'src/heap/mark-compact.h',
-  'src/heap/objects-visiting.h',
   'src/ic/ic.h',
   'src/json-stringifier.h',
   'src/keys.h',