3aa84906 changed native metadata serialization to use proper platform
session, but it caused a new bug: FirKLibSerializerExtension uses
FirProvider from the passed session to get a containing file of
serialized declaration to put some extension into the metadata. And
platform session doesn't contain information about any declarations
except platform ones
So it's needed to use the proper FirProvider in it, which can be
extracted from Fir2IrComponents. This provider contains providers from
all sessions that are being compiled plus providers for top-level
declarations generated by compiler plugins
^KT-65024 Fixed
Dmitriy Novozhilov
0741250b12