[FIR2IR] Generate property extension receiver references properly

compiler/testData/ir/irText/declarations/kt35550.fir.txt

@@ -9,7 +9,7 @@ FILE fqName:<root> fileName:/kt35550.kt
         $receiver: VALUE_PARAMETER name:<this> type:T of <root>.I.<get-id>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-id> <T> (): T of <root>.I.<get-id> declared in <root>.I'
-            ERROR_CALL 'Unresolved reference: this@R|/I.id|' type=T of <root>.I.<get-id>
+            GET_VAR '<this>: T of <root>.I.<get-id> declared in <root>.I.<get-id>' type=T of <root>.I.<get-id> origin=null
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any