[promises] Refactor debug code

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index 7532319bf2a8dc16f9f491b35933df73cbc6b2a6..976b8eccef2c5acf9ab3dc58c06a2232903783e5 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -8358,10 +8358,10 @@ Node* CodeStubAssembler::AllocatePromiseReactionJobInfo(
   StoreObjectFieldNoWriteBarrier(
       result, PromiseReactionJobInfo::kDeferredOnRejectOffset,
       deferred_on_reject);
-  StoreObjectFieldRoot(result, PromiseReactionJobInfo::kDebugIdOffset,
-                       Heap::kUndefinedValueRootIndex);
-  StoreObjectFieldRoot(result, PromiseReactionJobInfo::kDebugNameOffset,
-                       Heap::kUndefinedValueRootIndex);
+  StoreObjectFieldNoWriteBarrier(result, PromiseReactionJobInfo::kDebugIdOffset,
+                                 SmiConstant(0));
+  StoreObjectFieldNoWriteBarrier(result, PromiseReactionJobInfo::kDebugIdOffset,

[adamk, 2016/12/30 00:10:04]

I think this meant to say kDebugNameOffset.

[gsathya, 2016/12/30 01:48:51]

Done.

+                                 SmiConstant(DEBUG_NOT_ACTIVE));
   StoreObjectFieldNoWriteBarrier(result, PromiseReactionJobInfo::kContextOffset,
                                  context);
   return result;