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

Cleanup, and matches Chromium's build.

Review URL: https://codereview.chromium.org/1820583002

Cr-Commit-Position: refs/heads/master@{#34993}

.ycm_extra_conf.py

@@ -42,7 +42,7 @@ import sys
 # Flags from YCM's default config.
 flags = [
 '-DUSE_CLANG_COMPLETER',
-'-std=gnu++0x',
+'-std=gnu++11',
 '-x',
 'c++',
 ]

build/standalone.gypi

@@ -701,7 +701,7 @@
           '-Wnon-virtual-dtor',
           '-fno-exceptions',
           '-fno-rtti',
-          '-std=gnu++0x',
+          '-std=gnu++11',
         ],
         'ldflags': [ '-pthread', ],
         'conditions': [
@@ -751,7 +751,7 @@
           '-Wnon-virtual-dtor',
           '-fno-exceptions',
           '-fno-rtti',
-          '-std=gnu++0x',
+          '-std=gnu++11',
         ],
         'conditions': [
           [ 'visibility=="hidden"', {
@@ -981,7 +981,7 @@
           ['clang==1', {
             'xcode_settings': {
               'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
-              'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',  # -std=gnu++0x
+              'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',  # -std=c++11
             },
             'conditions': [
               ['v8_target_arch=="x64" or v8_target_arch=="arm64" \

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