[turbofan] Use CompareNilIC for abstract equality with null/undefined.

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 277dcb3b9a93476e6b549e841f0c45e58f7fb432..9b14bca9d70f51adb4d11c93aeb3ded3e72a7441 100644
--- a/src/full-codegen/x87/full-codegen-x87.cc
+++ b/src/full-codegen/x87/full-codegen-x87.cc
@@ -4860,8 +4860,8 @@ void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
   } else {
     Handle<Code> ic = CompareNilICStub::GetUninitialized(isolate(), nil);
     CallIC(ic, expr->CompareOperationFeedbackId());
-    __ test(eax, eax);
-    Split(not_zero, if_true, if_false, fall_through);
+    __ cmp(eax, isolate()->factory()->true_value());
+    Split(equal, if_true, if_false, fall_through);
   }
   context()->Plug(if_true, if_false);
 }