* tree-ssa-alias.c (compute_flow_insensitive_aliasing): If type
memory tag is call clobbered, so are its aliases.
(group_aliases): When two memory tags being grouped, if one is
call clobbered, so are the other and its aliases.
(add_may_alias): Remove call-clobbering stuff.
(replace_may_alias): Likewise.
(merge_pointed_to_info): Merge pt_global_mem