re PR tree-optimization/43879 (-fipa-pta causes various miscompilations)

re PR tree-optimization/43879 (-fipa-pta causes various miscompilations)

2010-04-28  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43879
	PR tree-optimization/43909
	* tree-ssa-structalias.c (struct variable_info): Add
	only_restrict_pointers flag.
	(new_var_info): Initialize it.  Increment stats.total_vars here.
	(create_function_info_for): Do not increment stats.total_vars
	here.
	(get_function_part_constraint): Fix build with C++.
	(insert_into_field_list): Remove.
	(push_fields_onto_fieldstack): Properly merge fields.
	(create_variable_info_for): Split and simplify.
	(create_variable_info_for_1): New piece.
	(intra_create_variable_infos): Properly make restrict constraints
	from parameters.

	* gcc.dg/ipa/ipa-pta-14.c: Adjust.

From-SVN: r158825