When we remove an RTL call, we wouldn't clean up references to the
return value of the call in debug insns.  Make it so that we do.


for  gcc/ChangeLog

	PR debug/89528
	* valtrack.c (dead_debug_insert_temp): Reset debug references
	to the return value of a call being removed.

for  gcc/testsuite/ChangeLog

	PR debug/89528
	* gcc.dg/guality/pr89528.c: New.

From-SVN: r270389