Adds couple of stats to remark emitter after Greedy RA:
- Number of spill/reload instructions without used in statepoint like instruction which does not suffer from stack usage.
- Cost of spill/reloads computed as block frequency for each stack usage.
- Number of copy instructions with virtual register operands.
- Cost of copies computed as block frequency for each copy.
While these numbers highly depends on MIR, they can show interesting information about changes in RA and even can be used as some metric.