Merge bleeding_edge.

src/msan.h

Index: src/msan.h
diff --git a/src/hydrogen-sce.h b/src/msan.h
similarity index 77%
copy from src/hydrogen-sce.h
copy to src/msan.h
index 55e153e0ed5ee3481669ee5c991f81238d51176e..484c9fa39797187597e534ca14ca8e89fd990135 100644
--- a/src/hydrogen-sce.h
+++ b/src/msan.h
@@ -25,24 +25,25 @@
 // (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_