re PR c/56113 (out of memory when compiling a function with many goto labels (50k > ))

2013-01-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/56113
	* tree-ssa-structalias.c (equiv_class_lookup): Also return
	the bitmap leader.
	(label_visit): Free duplicate bitmaps and record the leader instead.
	(perform_var_substitution): Adjust.

From-SVN: r195541