Filter out invalid slots in store buffer eagerly during object transition.

test/cctest/test-unboxed-doubles.cc

Index: test/cctest/test-unboxed-doubles.cc
diff --git a/test/cctest/test-unboxed-doubles.cc b/test/cctest/test-unboxed-doubles.cc
index 4989f8b53e97ccd7a6f4be490ed65f0eaa580375..c0a5886251868f10640c6d07e540531ba8d18d0b 100644
--- a/test/cctest/test-unboxed-doubles.cc
+++ b/test/cctest/test-unboxed-doubles.cc
@@ -1549,9 +1549,7 @@ static void TestWriteBarrierObjectShiftFieldsRight(
   }
 }
 
-
-// TODO(ishell): enable when this issue is fixed.
-DISABLED_TEST(WriteBarrierObjectShiftFieldsRight) {
+TEST(WriteBarrierObjectShiftFieldsRight) {
   TestWriteBarrierObjectShiftFieldsRight(OLD_TO_NEW_WRITE_BARRIER);
 }