[IR, Tests] Add context receivers count to IR dump

compiler/testData/ir/irText/declarations/contextReceivers/fromKEEP/monoidSum.ir.txt

@@ -137,6 +137,7 @@ FILE fqName:<root> fileName:/monoidSum.kt
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any
   FUN name:sum visibility:public modality:FINAL <T> ($receiver:kotlin.collections.List<T of <root>.sum>, <this>:<root>.Monoid<T of <root>.sum>) returnType:T of <root>.sum
     TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
+    contextReceiverParametersCount: 1
     $receiver: VALUE_PARAMETER name:<this> type:kotlin.collections.List<T of <root>.sum>
     VALUE_PARAMETER name:<this> index:0 type:<root>.Monoid<T of <root>.sum>
     BLOCK_BODY