cmake HAVE_WMEMCPY examples

libarchive/libarchive CMakeLists.txt :1574 

CHECK_FUNCTION_EXISTS(wmemcpy HAVE_WMEMCPY)

alibaba/AliSQLBackup storage/innobase/xtrabackup/src/libarchive/CMakeLists.txt :524 

CHECK_SYMBOL_EXISTS(wmemcpy "wchar.h" HAVE_WMEMCPY)