* sibcall.c (return_value_pseudo): New static variable.
	(skip_copy_to_return_value): Handle return_value_pseudo.
	(call_ends_block_p): Ensure that return_value_pseudo is set.
	(optimize_sibling_and_tail_recursive_call): Discover the
	load of pseudo return value in alternate exit block.

From-SVN: r44723