Refactor to combine HsLam and HsLamCase
This MR is pure refactoring (#23916 (closed)):
- Combine
HsLam
andHsLamCase
- Combine
HsCmdLam
andHsCmdLamCase
This just arranges to treat uniformly
\x -> e
\case pi -> ei
\cases pis -> ei
In the exising code base the first is treated differently to the latter two.
No change in behaviour.