* Adds a new to_boolean op to evaluate a value as a truthy i1
* Uses cascading scf.if ops to properly evaluate and/or sequences (short-circuit and original value returning)
* Adds a helper to construct select ops and uses it to implement 'not'
The secret here is LLVM_ENABLE_WARNINGS=ON.
I also fixed a couple warnings, which gets us to be warning-clean.
I noticed also that npcomp-run-mlir/basic.mlir seems to be failing.
Maybe something since the latest integrate. My next commit (introduce
npcomp mini runtime) will largely rewrite it though, so it'll get fixed
then.
* This is intended to provide low-level modeling for built-in objects.
* It is now possible to trace slice tuples (which are tuples of NoneType|EllipsisType|SlotObjectType<slice, ...>).