[turbofan] Fix bit representation of NumberConstant.

TEST=mjsunit/compiler/regress-bit-number-constant

Review URL: https://codereview.chromium.org/839813002

Cr-Commit-Position: refs/heads/master@{#25979}

src/compiler/representation-change.h

@@ -296,6 +296,13 @@ class RepresentationChanger {
         if (value == 0 || value == 1) return node;
         return jsgraph()->Int32Constant(1);  // value != 0
       }
+      case IrOpcode::kNumberConstant: {
+        double value = OpParameter<double>(node);
+        if (std::isnan(value) || value == 0.0) {
+          return jsgraph()->Int32Constant(0);
+        }
+        return jsgraph()->Int32Constant(1);
+      }
       case IrOpcode::kHeapConstant: {
         Handle<Object> handle = OpParameter<Unique<Object> >(node).handle();
         DCHECK(*handle == isolate()->heap()->true_value() ||

test/mjsunit/compiler/regress-bit-number-constant.js

+// Copyright 2015 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.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+var foo = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  function foo(i) {
+    return !(i ? 1 : false);
+  }
+  return {foo:foo};
+})(stdlib, foreign, buffer).foo;
+
+assertFalse(foo(1));