Small fixes/additions for 2.1.3

[Franz Sirl]

Hi,

some small things for 2.1.3:

	* sysdeps/unix/sysv/linux/execve.c: Add prototype for __syscall_execve.
	* sysdeps/unix/sysv/linux/setrlimit.c: Add prototype for
	__syscall_setrlimit.
	* sysdeps/unix/sysv/linux/powerpc/syscalls.list: Add setrlimit.
	* sysdeps/powerpc/stackinfo.h: New file.

Uli, would you please consider the loader patch Geoff posted on libc-hacker for
2.1.3? It solves the mozilla problem for us and seems to have no negative
effects so far. We are still tracking a pthread related bug (__m_kind gets
corrupted) with mozilla, but probably can't finish that before 2.1.3.

Thanks,
Franz.