Use c++1y for cxxreact

Reviewed By: mhorowitz

Differential Revision: D3852279

fbshipit-source-id: a7b80170d6b86428db47c15bbf02d68d293112fc

ReactCommon/cxxreact/BUCK

@@ -91,7 +91,7 @@ cxx_library(
     '-fno-omit-frame-pointer',
     '-Wall',
     '-Werror',
-    '-std=c++11',
+    '-std=c++1y',
     '-fexceptions',
   ],
   deps = [
@@ -167,6 +167,7 @@ react_library(
     '-fexceptions',
     '-fvisibility=hidden',
     '-frtti',
+    '-std=c++1y',
   ] + REACT_LIBRARY_EXTRA_COMPILER_FLAGS,
   deps = [
     ':module',