* Makefile.in (DLL_OFILES): Add arc4random.o.
	* common.din: Export arc4random, arc4random_addrandom, arc4random_buf,
	arc4random_stir and arc4random_uniform.
	* mktemp.cc (arc4random): Remove static replacement function.
	* posix.sgml (std-bsd): Add arc4random functions.
	* include/cygwin/stdlib.h: Declare arc4random functions.
	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
	* libc/arc4random.cc: New file implementing arc4random functions taken
	from FreeBSD.
	Add missing ChangeLog entry for former checkin.
	* new-features.sgml (ov-new1.7.19): Add arc4random,
	arc4random_addrandom, arc4random_buf, arc4random_stir and
	arc4random_uniform.
	* gdb.base/filesym.exp: Use gdb_test_multiple instead of
	gdb_expect.
	Add test to flush the remaining input buffer so that this
	file passes testsuite/12649.