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

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index 39a826c4091609127f4aaf874f297fed488a241f..4908e8d641c97fdf2483419d28136f264b0c02d7 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -636,9 +636,8 @@ void FullCodeGenerator::DoTest(Expression* condition,
                                Label* fall_through) {
   Handle<Code> ic = ToBooleanStub::GetUninitialized(isolate());
   CallIC(ic, condition->test_id());
-  __ testp(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);
 }
 
 
@@ -2007,8 +2006,8 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       CallLoadIC(NOT_INSIDE_TYPEOF);  // rax=result.done
       Handle<Code> bool_ic = ToBooleanStub::GetUninitialized(isolate());
       CallIC(bool_ic);
-      __ testp(result_register(), result_register());
-      __ j(zero, &l_try);
+      __ CompareRoot(result_register(), Heap::kTrueValueRootIndex);
+      __ j(not_equal, &l_try);
 
       // result.value
       __ Pop(load_receiver);                             // result