alias.c (find_base_term): Avoid redundant and not used recursion.

2013-03-26  Richard Biener  <rguenther@suse.de>

	* alias.c (find_base_term): Avoid redundant and not used
	recursion.
	(base_alias_check): Get the initial base term from the
	caller.
	(true_dependence_1): Compute and pass base terms to base_alias_check.
	(write_dependence_p): Likewise.
	(may_alias_p): Likewise.

From-SVN: r197110