Reland [heap] Avoid the use of cells to point from code to new-space objects.

src/ia32/assembler-ia32-inl.h

Index: src/ia32/assembler-ia32-inl.h
diff --git a/src/ia32/assembler-ia32-inl.h b/src/ia32/assembler-ia32-inl.h
index 2120a90e0ceda66820b8a9c54a82571ffac3f39a..e72b4072c469e4afe14ae988c519d112b2b421f9 100644
--- a/src/ia32/assembler-ia32-inl.h
+++ b/src/ia32/assembler-ia32-inl.h
@@ -137,8 +137,7 @@ void RelocInfo::set_target_object(Object* target,
   if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
       host() != NULL &&
       target->IsHeapObject()) {
-    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
-        host(), this, HeapObject::cast(target));
+    host()->GetHeap()->RecordWriteIntoCode(host(), this, target);
   }
 }
 
@@ -341,7 +340,6 @@ Immediate::Immediate(Handle<Object> handle) {
   // Verify all Objects referred by code are NOT in new space.
   Object* obj = *handle;
   if (obj->IsHeapObject()) {
-    DCHECK(!HeapObject::cast(obj)->GetHeap()->InNewSpace(obj));
     x_ = reinterpret_cast<intptr_t>(handle.location());
     rmode_ = RelocInfo::EMBEDDED_OBJECT;
   } else {
@@ -380,7 +378,6 @@ void Assembler::emit(Handle<Object> handle) {
   AllowDeferredHandleDereference heap_object_check;
   // Verify all Objects referred by code are NOT in new space.
   Object* obj = *handle;
-  DCHECK(!isolate()->heap()->InNewSpace(obj));
   if (obj->IsHeapObject()) {
     emit(reinterpret_cast<intptr_t>(handle.location()),
          RelocInfo::EMBEDDED_OBJECT);