Introduce flag --allocation-site-transitioning

src/code-stubs.h

 // 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.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 2059 matching lines @@
 class ArrayConstructorStubBase : public HydrogenCodeStub {
  public:
   ArrayConstructorStubBase(Isolate* isolate,
                            ElementsKind kind,
                            AllocationSiteOverrideMode override_mode)
       : HydrogenCodeStub(isolate) {
     // It only makes sense to override local allocation site behavior
     // if there is a difference between the global allocation site policy
     // for an ElementsKind and the desired usage of the stub.
     DCHECK(override_mode != DISABLE_ALLOCATION_SITES ||
+           !FLAG_allocation_site_transitioning ||
            AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE);
     set_sub_minor_key(ElementsKindBits::encode(kind) |
                       AllocationSiteOverrideModeBits::encode(override_mode));
   }
 
   ElementsKind elements_kind() const {
     return ElementsKindBits::decode(sub_minor_key());
   }
 
   AllocationSiteOverrideMode override_mode() const {
@@ skipping 396 matching lines @@
 
 #undef DEFINE_CALL_INTERFACE_DESCRIPTOR
 #undef DEFINE_PLATFORM_CODE_STUB
 #undef DEFINE_HANDLER_CODE_STUB
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_