[turbofan] NaN is never truish.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 3623 matching lines @@
   return NewNode(jsgraph()->machine()->Store(representation),
                  jsgraph()->ExternalConstant(reference),
                  jsgraph()->IntPtrConstant(0), value);
 }
 
 
 Node* AstGraphBuilder::BuildToBoolean(Node* input) {
   // TODO(bmeurer, mstarzinger): Refactor this into a separate optimization
   // method.
   switch (input->opcode()) {
-    case IrOpcode::kNumberConstant:
-      return jsgraph_->BooleanConstant(!NumberMatcher(input).Is(0));
+    case IrOpcode::kNumberConstant: {
+      NumberMatcher m(input);
+      return jsgraph_->BooleanConstant(!m.Is(0) && !m.IsNaN());
+    }
     case IrOpcode::kHeapConstant: {
       Handle<HeapObject> object = HeapObjectMatcher(input).Value().handle();
       return jsgraph_->BooleanConstant(object->BooleanValue());
     }
     case IrOpcode::kJSEqual:
     case IrOpcode::kJSNotEqual:
     case IrOpcode::kJSStrictEqual:
     case IrOpcode::kJSStrictNotEqual:
     case IrOpcode::kJSLessThan:
     case IrOpcode::kJSLessThanOrEqual:
@@ skipping 478 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8