Merging r228353: ------------------------------------------------------------------------ r228353 | ericwf | 2015-02-05 15:01:40 -0800 (Thu, 05 Feb 2015) | 1 line Remove use of _[A-Z] identifiers and poison them to detect usage ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/libcxx/branches/release_36@228668 91177308-0d34-0410-b5e6-96231b3b80d8