tree-ssa-alias.c (decl_refs_may_alias_p): Add size1 and size2 parameters; return...

tree-ssa-alias.c (decl_refs_may_alias_p): Add size1 and size2 parameters; return early for must-alias.

	* tree-ssa-alias.c (decl_refs_may_alias_p): Add size1 and size2
	parameters; return early for must-alias.
	(indirect_ref_may_alias_decl_p): Likewise; when establishing
	outer types match, try nonoverlapping_component_refs
	if must-alias is not obvious.
	(indirect_refs_may_alias_p): Likewise.
	(refs_may_alias_p_2): Likewise.

	* gcc.dg/tree-ssa/alias-access-path-3.c: New testcase.
	* gcc.dg/tree-ssa/alias-access-path-8.c: New testcase.

From-SVN: r273079