Fix yield conversion of scf.if/scf.for to emitc

[josel-amd]

No description provided.

[mgehre-amd]

Did you check the technique used in the FuncToEmitC conversion? Is that different/the same?

[josel-amd]

Did you check the technique used in the FuncToEmitC conversion? Is that different/the same?

Yes. We're doing almost the same. The difference here is that the yield conversion that seems to be unique since, in this case, we need to convert an yield into an emitc.assign

More details: By doing almost the same I mean calling rewriter.convertRegionTypes(), calling the inlineRegionBefore function and not using the body given by the adaptor.

[mgehre-amd]

Looks great!