Surya's recent patch to IRA improves the code for sh/pr54602-1.c 
slightly.  Specifically it's able to eliminate a save/restore in the 
prologue/epilogue and a bit of register shuffling.

As a result there literally aren't any insns that can be used to fill 
the delay slot of the return, so a nop gets emitted and the test fails.

Given there literally aren't any insns to move into the delay slot, the 
best course of action is to just drop the test.

Pushed to the trunk.

Jeff