When given a register and an immediate, it would generate imul imm,dst,dst however the 64-bit prefix was generated wrong and if dst was an extended register only the first operand would be an extended register. To fix this, change IMUL2 to not work on immediates anymore, and added a new IMUL3 that takes a destination register, source register, and immediate. Also, change compiler.cfg.two-operand to not two-operandize %mul-imm, since this isn't needed anymore.
This fixes the sporadic benchmark.tuple-arrays crash on 64-bit machines.
- 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
- new map-flat combinator replaces usages of 'map flatten' in compiler
- compiler.tree.def-use.simplified uses an explicit accumulator instead of flatten
- compiler.tree.tuple-unboxing uses an explicit accumulator instead of flatten
- fix inlining regression from last time: custom inlining results would sometimes be discarded
- compiler.tree's 3each and 3map combinators rewritten to not use flip
- rewrite math.partial-dispatch without locals (purely stylistic, no performance increase)
- hand-optimize flip for common arrays-of-arrays case
- don't run escape analysis and tuple unboxing if there are no allocations in the IR