re PR middle-end/58145 (volatileness of write is discarded, perhaps in "lim1" related to loop optimizations)

	PR tree-optimization/58145
	* tree-sra.c (build_ref_for_offset): If prev_base has
	TREE_THIS_VOLATILE or TREE_SIDE_EFFECTS, propagate it to MEM_REF.

	* gcc.dg/pr58145-1.c: New test.
	* gcc.dg/pr58145-2.c: New test.

From-SVN: r201748