FIR: Transform synthetic calls children even without incomplete candidate

It might be necessary for cases like
run @l1{
   run {
      if (...) return@l1 1
   }
}

"if" is a synthetic call, but without candidate since there's just one branch
But return@l1 1 is incomplete because it's resolved in dependent context
and "1" is hang incomplete integer literal

compiler/testData/diagnostics/tests/inference/regressions/kt36342_2.fir.kt

@@ -5,7 +5,7 @@ fun <M> materialize(): M = TODO()
 
 fun test(b: Boolean) {
     <!INAPPLICABLE_CANDIDATE!>id<!>(if (b) {
-        id(<!UNRESOLVED_REFERENCE!>unresolved<!>)
+        <!INAPPLICABLE_CANDIDATE!>id<!>(<!UNRESOLVED_REFERENCE!>unresolved<!>)
     } else {
         id(
             materialize()