Import some <stdlib.h> function declarations from latest FreeBSD and
implement them. I am not sure if we should call the global reent
cleanup in quick_exit() similar to exit().
newlib/ChangeLog
2015-10-14 Sebastian Huber <sebastian.huber@embedded-brains.de>
* libc/include/stdlib.h (at_quick_exit): Declare.
(quick_exit): Likewise.
* libc/stdlib/Makefile.am (GENERAL_SOURCES): Add
quick_exit.c.
* libc/stdlib/Makefile.in: Regenerate.
* libc/stdlib/quick_exit.c: New.
Sebastian Huber