* dwarf2expr.c (new_dwarf_expr_context): Set ``stack_len'' to

	* dwarf2expr.c (new_dwarf_expr_context): Set ``stack_len'' to
	correctly indicate an empty stack and ``stack_allocated'' to the
	indicate the number of elements initially allocated.
	(dwarf_expr_grow_stack): Simplify method for computing new
	stack size.  Don't loop infinitely if ``stack_len'' is zero.
	(execute_stack_op): Move ``ctx->in_reg'' initialization
	out of loop.  Allow DW_OP_reg0 ... DW_OP_reg31 and DW_OP_regx to
	be used in conjuction with DW_OP_piece.  Revise error message
	accordingly.