backport: re PR ipa/77587 (C compiler produces incorrect stack alignment with __attri...

backport: re PR ipa/77587 (C compiler produces incorrect stack alignment with __attribute__((weak)))

	Backported from mainline
	2016-09-19  Jakub Jelinek  <jakub@redhat.com>
		    Jan Hubicka  <jh@suse.cz>

	PR target/77587
	* cgraph.c (cgraph_node::rtl_info): Pass &avail to
	ultimate_alias_target call, return NULL if avail < AVAIL_AVAILABLE.
	Call ultimate_alias_target just once, not up to 4 times.

	* gcc.dg/pr77587.c: New test.
	* gcc.dg/pr77587a.c: New file.

From-SVN: r248609