* src/closures.c: Include sys/statfs.h.
	(_GNU_SOURCE): Define on Linux.
	(FFI_MMAP_EXEC_SELINUX): Define.
	(selinux_enabled): New variable.
	(selinux_enabled_check): New function.
	(is_selinux_enabled): Define.
	(dlmmap): Use it.

	* configure.ac (NO_EXECUTE_PERMISSION): Set by default.
	* configure: Rebuilt.

From-SVN: r123457