We cannot always return null, because in such case some expressions
would become not fully explorable from the types perspective (see
the documentation on the `getCorrespondingTypeIfPossible`)
`FirNamedReference` might appear when resolving method references (like
`foo::bar`), but also when IJ Platform tries to resolve other parts of
the Kotlin PSI, notably a `KtNameReferenceExpression` in a
function call (`bar` in `foo.bar(baz)` expression).
N.B. FE10 implementation does not support returning `null` as a type -
currently it always returns `Unit` type in case it cannot figure out
the actual type. This issue should probably be tackled together with
KT-60166, so that both implementations are more or less aligned
^KT-60341 Fixed
^KT-59077 Fixed
^KTIJ-25745 Fixed
Roman Golyshev
b8052761db