Improve detection of C++11 features.

src/checks.h

Index: src/checks.h
diff --git a/src/checks.h b/src/checks.h
index b309e2c42c79361b53d7eacaaf6d75028d1a64d5..7c15588b4a5ad36c8e246e6b0006de8ee1b8e126 100644
--- a/src/checks.h
+++ b/src/checks.h
@@ -30,7 +30,8 @@
 
 #include <string.h>
 
-#include "../include/v8stdint.h"
+#include "globals.h"
+
 extern "C" void V8_Fatal(const char* file, int line, const char* format, ...);
 
 // The FATAL, UNREACHABLE and UNIMPLEMENTED macros are useful during
@@ -232,7 +233,7 @@ inline void CheckNonEqualsHelper(const char* file,
 
 // Use C++11 static_assert if possible, which gives error
 // messages that are easier to understand on first sight.
-#if __cplusplus >= 201103L
+#if defined(V8_HAVE_CXX11_STATIC_ASSERT)
 #define STATIC_CHECK(test) static_assert(test, #test)
 #else
 // This is inspired by the static assertion facility in boost.  This