cmake HAVE_FILE_DEF examples

fluffos/fluffos src/thirdparty/libevent/cmake/Macros.cmake :32 

CHECK_INCLUDE_FILES("${EVENT_INCLUDES};${FILE}" ${HAVE_FILE_DEF})

CTSRD-CHERI/cheribsd contrib/libevent/cmake/Macros.cmake :32 

CHECK_INCLUDE_FILES("${EVENT_INCLUDES};${FILE}" ${HAVE_FILE_DEF})

CTSRD-CHERI/cheribsd contrib/ntp/sntp/libevent/cmake/Macros.cmake :32 

CHECK_INCLUDE_FILES("${EVENT_INCLUDES};${FILE}" ${HAVE_FILE_DEF})