PR27736: Fix bootstrap fallout from PR25514

[Roger Sayle]

On Tue, 23 May 2006, Richard Sandiford wrote:
>
> 	PR rtl-optimization/27736
> 	* combine.c (replaced_rhs_value): New variable.
> 	(combine_instructions): Set it.
> 	(distribute_notes): When distributing a note in replaced_rhs_insn,
> 	check whether the value was used in replaced_rhs_value.

This is OK for mainline.  Thanks for fixing the fallout so quickly.

Roger
--