* Add an early `TailMerge` pass
Some translations can have a lot of guest calls and since for each guest
call there is a call guard which may return. This can produce a lot of
epilogue code for returns. This pass merges the epilogue into a single
block.
```
Using filter 'hcq'.
Using metric 'code size'.
Total diff: -1648111 (-7.19 %) (bytes):
Base: 22913847
Diff: 21265736
Improved: 4567, regressed: 14, unchanged: 144
```
* Set PTC version
* Address feedback
* Handle `void` returning functions
* Actually handle `void` returning functions
* Fix `RegisterToLocal` logging
