X87: [compiler] Drop the CompareNilIC.

src/full-codegen/x87/full-codegen-x87.cc

Index: src/full-codegen/x87/full-codegen-x87.cc
diff --git a/src/full-codegen/x87/full-codegen-x87.cc b/src/full-codegen/x87/full-codegen-x87.cc
index 1c049d7a30dc82d97316ba4242e4d4ca80ebf2a3..b11b09bf995c3b933344834a725def74e6596870 100644
--- a/src/full-codegen/x87/full-codegen-x87.cc
+++ b/src/full-codegen/x87/full-codegen-x87.cc
@@ -3887,10 +3887,11 @@ void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
     __ cmp(eax, nil_value);
     Split(equal, if_true, if_false, fall_through);
   } else {
-    Handle<Code> ic = CompareNilICStub::GetUninitialized(isolate(), nil);
-    CallIC(ic, expr->CompareOperationFeedbackId());
-    __ cmp(eax, isolate()->factory()->true_value());
-    Split(equal, if_true, if_false, fall_through);
+    __ JumpIfSmi(eax, if_false);
+    __ mov(eax, FieldOperand(eax, HeapObject::kMapOffset));
+    __ test_b(FieldOperand(eax, Map::kBitFieldOffset),
+              1 << Map::kIsUndetectable);
+    Split(not_zero, if_true, if_false, fall_through);
   }
   context()->Plug(if_true, if_false);
 }