re PR middle-end/29215 (extra store for memcpy)

re PR middle-end/29215 (extra store for memcpy)

	PR middle-end/29215
	* builtins.c (SLOW_UNALIGNED_ACCESS): Define if not defined.
	(fold_builtin_memory_op): Handle even the case where just one
	of src and dest is an address of a var decl component, using
	TYPE_REF_CAN_ALIAS_ALL pointers.  Remove is_gimple_min_invariant
	and readonly_data_expr src check.
	* tree-ssa-sccvn.c (DFS): Use clear_and_done_ssa_iter to shut
	up warnings.

	* trans-array.c (trans_array_constructor_value,
	gfc_build_constant_array_constructor): Fill in TREE_PURPOSE.

	* gfortran.dg/array_memcpy_3.f90: Adjust pattern to match even
	memcpy optimized into ref-all store.
	* gcc.dg/pr29215.c: New test.

From-SVN: r142061