* tree-dfa.c (add_referenced_var): Only global variables are
	call-clobbered.
	* tree-flow.h (struct ptr_info_def): Add field pt_global_mem.
	* tree-ssa-alias.c (compute_points_to_and_addr_escape): Mark
	all pointers dereferenced if the statement dereferences them.
	(create_name_tags): Do not create memory tags for pointers
	that have PT_ANYTHING set.
	Also check if PT_VARS is not empty before creating a name tag.
	(compute_flow_sensitive_aliasing): Don't mark call-clobbered
	variables that share the same alias set with a pointer that
	may point anywhere.
	(add_may_alias): Add FIXME comment to remove clobbering
	aliased variables and tags.
	(replace_may_alias): Likewise.
	(set_pt_anything): Do not clear PT_VARS nor IS_DEREFERENCED.
	(merge_pointed_to_info): If the original variable has not
	points-to information, call set_pt_anything.
	(add_pointed_to_var): Do not prevent adding a pointed-to
	variable if the pointers is PT_ANYTHING.
	If the variable is a global, set PT_GLOBAL_MEM.
	(collect_points_to_info_r): Don't assume that PLUS_EXPRs of
	pointer type only come in PTR+OFFSET flavours.
	Always call merge_pointed_to_info on PHI arguments that are
	SSA_NAMEs.
	(get_nmt_for): Mark call-clobbered tags whose pointer points
	to global memory.
	* tree-ssa-operands.c (opf_kill_def, opf_no_vops): Switch
	values.
	(get_indirect_ref_operands): Always clear OPF_KILL_DEF from
	FLAGS.
	(add_stmt_operand): Abort if the caller tried to add a killing
	definition for a memory tag.
	* tree-ssa.c (verify_flow_sensitive_alias_info): Remove
	unnecessary checks.

From-SVN: r86198