FIR2IR: add extension receiver parameters to functions

compiler/testData/ir/irText/expressions/boundCallableReferences.fir.txt

@@ -32,7 +32,8 @@ FILE fqName:<root> fileName:/boundCallableReferences.kt
       overridden:
         public open fun toString (): kotlin.String declared in kotlin.Any
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any 
-  FUN name:qux visibility:public modality:FINAL <> () returnType:kotlin.Unit 
+  FUN name:qux visibility:public modality:FINAL <> ($receiver:<root>.A) returnType:kotlin.Unit
+    $receiver: VALUE_PARAMETER name:<this> type:<root>.A
     BLOCK_BODY
   PROPERTY name:test1 visibility:public modality:FINAL [val] 
     FIELD PROPERTY_BACKING_FIELD name:test1 type:IrErrorType visibility:public [final,static]