* ldlang.c (Scan_for_self_assignment): Check an assignment tree to

* ldlang.c (Scan_for_self_assignment): Check an assignment tree to
	see if the same value is being used on the rhs as on the lhs.
	(print_assignment): Call scan_for_self_assignment and if it
	returns true, do no display the result of the computation but
	instead just the final value of the symbol on the lhs.
* ld.texinfo: Document this behaviour and provide an example of
	when it will happen.