insert spill before reload to fix x86-32 regression
inactive splitting: if all inactive intervals' registers are in use, don't fail
fix stack analysis tests
- new-insn word to construct instructions
- cache RPO in the CFG
- re-organize low-level optimizer so that MR is built after register allocation
- register allocation now stores instruction numbers in the instructions themselves
- split defs-vregs into defs-vregs and temp-vregs
Slava Pestov