Remove support for Object.observe

src/ic/s390/ic-s390.cc

Index: src/ic/s390/ic-s390.cc
diff --git a/src/ic/s390/ic-s390.cc b/src/ic/s390/ic-s390.cc
index 57315709739a20f3e99fb1617487f40106c0d45f..bf9f8a1d716794ae0ce21eaa67ecd5892f237b0a 100644
--- a/src/ic/s390/ic-s390.cc
+++ b/src/ic/s390/ic-s390.cc
@@ -625,11 +625,10 @@ void KeyedStoreIC::GenerateMegamorphic(MacroAssembler* masm,
   __ JumpIfSmi(receiver, &slow);
   // Get the map of the object.
   __ LoadP(receiver_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
-  // Check that the receiver does not require access checks and is not observed.
-  // The generic stub does not perform map checks or handle observed objects.
+  // Check that the receiver does not require access checks.
+  // The generic stub does not perform map checks.
   __ LoadlB(ip, FieldMemOperand(receiver_map, Map::kBitFieldOffset));
-  __ AndP(r0, ip,
-          Operand(1 << Map::kIsAccessCheckNeeded | 1 << Map::kIsObserved));
+  __ AndP(r0, ip, Operand(1 << Map::kIsAccessCheckNeeded));
   __ bne(&slow, Label::kNear);
   // Check if the object is a JS array or not.
   __ LoadlB(r6, FieldMemOperand(receiver_map, Map::kInstanceTypeOffset));