In some cases we transform flexible type into non-flexible during
enhancement, but don't add `@EnhancedNullability` attribute to them,
which breaks consistency with K1 on IR level
This commit fixes it
^KT-65302
This fixes a bunch of missing overridden symbols in IR.
This is also required for fixing KT-59921 in the following commit
where we need to keep all overridden symbols of intersection overrides
so that we can enhance them properly.
#KT-57300 Fixed
#KT-57299 Fixed
#KT-59921
#KT-57300
#KT-62788
#KT-64271
#KT-64382
Dmitriy Novozhilov