[FIR] Use tower to resolve delegated constructors, set dispatch receiver

compiler/testData/ir/irText/classes/innerClassWithDelegatingConstructor.fir.txt

@@ -28,6 +28,7 @@ FILE fqName:<root> fileName:/innerClassWithDelegatingConstructor.kt
         $outer: VALUE_PARAMETER name:<this> type:<root>.Outer
         BLOCK_BODY
           DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> (x: kotlin.Int) [primary] declared in <root>.Outer.Inner'
+            $this: GET_VAR '<this>: <root>.Outer declared in <root>.Outer' type=<root>.Outer origin=null
             x: CONST Int type=kotlin.Int value=0
       FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
         overridden: