In IR interpreter we have "preprocessors". Preprocessor is a
transformer that changes IR expressions in a way that we can
interpret them at least partially.
We have two places where interpretation is happening:
1. Right after fir2ir where we evaluate only strictly necessary
expression for `const val` and annotations.
2. In lowering for every backend where we are doing some
constant folding.
Earlier, to avoid double work, we didn't launch preprocessors
in backend if we were using K2. But this approach breaks compilation
for MPP projects where one module is compiled with K1 into klib
and the overall project is compiled with K2. On the backend side,
we are mistakenly assuming that preprocessors were launched, but they
were not.
The solution is to run preprocessors only on the backend side. If we
think about it, interpretation on fir2ir doesn't require any
preprocessing because we are working only with expressions that are
correct and must be fully evaluated.
#KT-62126 Fixed
Ivan Kylchik
70f195598e