7bcd3c7948
FirExtensionRegistrar is FIR specific extension which requires FIR classes to work, which are missing in dependencies of FE 1.0 IDE plugin. To fix this issue FirExtensionRegistrarAdapter is introduced. This class is a base class for FirExtensionRegistrar and it does not have any FIR specific classes in it's API, so it can be safely registered in IDE