Use C++11 / gnu++11, not 0x

include/v8config.h

Index: include/v8config.h
diff --git a/include/v8config.h b/include/v8config.h
index d2be68561c0cc3807040b65cd4a4d397ce102afe..ce3a9d2f4f66208810379ef6e9e080ab2ab04459 100644
--- a/include/v8config.h
+++ b/include/v8config.h
@@ -266,13 +266,7 @@
 # define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
 # define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
 
-// g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
-// without warnings (functionality used by the macros below).  These modes
-// are detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or,
-// more standardly, by checking whether __cplusplus has a C++11 or greater
-// value. Current versions of g++ do not correctly set __cplusplus, so we check
-// both for forward compatibility.
-# if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
+# if __cplusplus >= 201103L
 #  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
 #  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
 # endif