* expr.c (store_constructor): Allow variable bounds of array type.
	(expand_expr): Don't blow up if type is ERROR_MARK.
	* varasm.c (output_constructor): Don't access lower bound of array
	type unless need it if index is supplied (so it can be a variable
	if no index is supplied).
	Use tree_low_cst; use HOST_WIDE_INT for sizes; change BITPOS to POS.
	Other minor cleanups.

From-SVN: r36060