Merge bleeding_edge.

src/msan.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_HYDROGEN_SCE_H_
-#define V8_HYDROGEN_SCE_H_
+// MemorySanitizer support.
 
-#include "hydrogen.h"
+#ifndef V8_MSAN_H_
+#define V8_MSAN_H_
 
-namespace v8 {
-namespace internal {
+#ifndef __has_feature
+# define __has_feature(x) 0
+#endif
 
+#if __has_feature(memory_sanitizer) && !defined(MEMORY_SANITIZER)
+# define MEMORY_SANITIZER
+#endif
 
-class HStackCheckEliminationPhase : public HPhase {
- public:
-  explicit HStackCheckEliminationPhase(HGraph* graph)
-      : HPhase("H_Stack check elimination", graph) { }
+#ifdef MEMORY_SANITIZER
+# include <sanitizer/msan_interface.h>
+// Marks a memory range as fully initialized.
+# define MSAN_MEMORY_IS_INITIALIZED(p, s) __msan_unpoison((p), (s))
+#else
+# define MSAN_MEMORY_IS_INITIALIZED(p, s)
+#endif
 
-  void Run();
-};
-
-
-} }  // namespace v8::internal
-
-#endif  // V8_HYDROGEN_SCE_H_
+#endif  // V8_MSAN_H_