-- require a fixup.
--
handleComponent delta instr
- (CyclicSCC ( (vreg, InReg sreg, [InReg dreg]) : rest))
+ (CyclicSCC ( (vreg, InReg sreg, (InReg dreg: _)) : rest))
+ -- dest list may have more than one element, if the reg is also InMem.
= do
-- spill the source into its slot
(instrSpill, slot)