revert: builtins.c (fold_builtin_memory_op): Use the alias oracle to query if the memory regions for memmove overlap.

2009-09-02  Richard Guenther  <rguenther@suse.de>

        Revert
        2009-08-31  Richard Guenther  <rguenther@suse.de>

        * builtins.c (fold_builtin_memory_op): Use the alias oracle
        to query if the memory regions for memmove overlap.
        * tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Relax the
        asserts on pointers, instead deal with odd trees.
        (ptr_derefs_may_alias_p): Likewise.
        (refs_may_alias_p_1): Constructor bases also never alias.

From-SVN: r151320