X87: [turbofan] Desugar JSUnaryNot(x) to Select(x, false, true).

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 486ddd93e45ea5d631f2272a23f6b7026502213b..bafd91908d77e06a0dabead94ba42d8cd23e6370 100644
--- a/src/full-codegen/x87/full-codegen-x87.cc
+++ b/src/full-codegen/x87/full-codegen-x87.cc
@@ -621,9 +621,8 @@ void FullCodeGenerator::DoTest(Expression* condition,
                                Label* fall_through) {
   Handle<Code> ic = ToBooleanStub::GetUninitialized(isolate());
   CallIC(ic, condition->test_id());
-  __ test(result_register(), result_register());
-  // The stub returns nonzero for true.
-  Split(not_zero, if_true, if_false, fall_through);
+  __ CompareRoot(result_register(), Heap::kTrueValueRootIndex);
+  Split(equal, if_true, if_false, fall_through);
 }
 
 
@@ -1977,8 +1976,8 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       CallLoadIC(NOT_INSIDE_TYPEOF);  // result.done in eax
       Handle<Code> bool_ic = ToBooleanStub::GetUninitialized(isolate());
       CallIC(bool_ic);
-      __ test(eax, eax);
-      __ j(zero, &l_try);
+      __ CompareRoot(result_register(), Heap::kTrueValueRootIndex);
+      __ j(not_equal, &l_try);
 
       // result.value
       __ pop(load_receiver);                              // result