[heap] no longer perform GC to make heap iterable.

src/debug/liveedit.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/liveedit.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/compiler.h"
@@ skipping 710 matching lines @@
 
 // Finds all references to original and replaces them with substitution.
 static void ReplaceCodeObject(Handle<Code> original,
                               Handle<Code> substitution) {
   // Perform a full GC in order to ensure that we are not in the middle of an
   // incremental marking phase when we are replacing the code object.
   // Since we are not in an incremental marking phase we can write pointers
   // to code objects (that are never in new space) without worrying about
   // write barriers.
   Heap* heap = original->GetHeap();
-  HeapIterator iterator(heap);
+  HeapIterator iterator(heap, HeapIterator::kFilterUnreachable);
   // Now iterate over all pointers of all objects, including code_target
   // implicit pointers.
   for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
     if (obj->IsJSFunction()) {
       JSFunction* fun = JSFunction::cast(obj);
       if (fun->code() == *original) fun->ReplaceCode(*substitution);
     } else if (obj->IsSharedFunctionInfo()) {
       SharedFunctionInfo* info = SharedFunctionInfo::cast(obj);
       if (info->code() == *original) info->set_code(*substitution);
     }
@@ skipping 653 matching lines @@
                                     Handle<FixedArray> result,
                                     int len) {
   Isolate* isolate = shared_info_array->GetIsolate();
   bool found_suspended_activations = false;
 
   DCHECK_LE(len, result->length());
 
   FunctionPatchabilityStatus active = FUNCTION_BLOCKED_ACTIVE_GENERATOR;
 
   Heap* heap = isolate->heap();
-  HeapIterator iterator(heap);
+  HeapIterator iterator(heap, HeapIterator::kFilterUnreachable);
   HeapObject* obj = NULL;
   while ((obj = iterator.next()) != NULL) {
     if (!obj->IsJSGeneratorObject()) continue;
 
     JSGeneratorObject* gen = JSGeneratorObject::cast(obj);
     if (gen->is_closed()) continue;
 
     HandleScope scope(isolate);
 
     for (int i = 0; i < len; i++) {
@@ skipping 230 matching lines @@
     scope_info_length++;
 
     current_scope = current_scope->outer_scope();
   }
 
   return scope_info_list;
 }
 
 }  // namespace internal
 }  // namespace v8