The problem here is that for common session we register `FirJavaElementFinder`
which provides light classes based on expect classes. And then
at the start of analysis of jvm module we register one another
`FirJavaElementFinder`, which sees actual classes and uses them to
build light classes
But, because class ids of expect and actual class pair are the same and
element finders are ordered by creation order, when java resolve tries
to resolve some class, it founds light class based on expect class,
even if we are already in platform session
To fix this problem, it was decided to unregister all previous element
finders on creation of each new session, so old finders won't interfere
with analysis
^KT-63612 Fixed
^KT-64296
Dmitriy Novozhilov
f4e3203cd8