Now FE IR -> BE IR transformation is performed in multiple stages
controller by Fir2IrConverter. Stages are
* files & classes registration
* supertypes & type parameters handling
* functions & properties signature generation
* body generation
After each step we have guarantee (with exception of local classes &
type inference combination, and external symbols) that required symbols
(class/function/property/variable/type parameter)
are already bound to real declarations and have correct parents.
This commit also fixes incorrect parents for local classes
Anonymous classes for local function references implement their
getOwner() as "return null" currently (KT-14291). To avoid NPE in this
case, we now consider two local functions the same if their name and
signature are equal. This is incorrect in general, but unlikely to cause
major problems and is going to be fixed by KT-14291 eventually anyway
#KT-17055
Svyatoslav Kuzmich