FIR: set super type reference properly

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSuperReference.kt

@@ -11,6 +11,8 @@ import org.jetbrains.kotlin.fir.visitors.FirVisitor
 interface FirSuperReference : FirReference {
     val superTypeRef: FirTypeRef
 
+    fun replaceSuperTypeRef(newSuperTypeRef: FirTypeRef)
+
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R =
         visitor.visitSuperReference(this, data)
 

compiler/fir/tree/src/org/jetbrains/kotlin/fir/references/FirExplicitSuperReference.kt

@@ -15,6 +15,10 @@ class FirExplicitSuperReference(
     psi: PsiElement?,
     override var superTypeRef: FirTypeRef
 ) : FirAbstractElement(session, psi), FirSuperReference {
+    override fun replaceSuperTypeRef(newSuperTypeRef: FirTypeRef) {
+        superTypeRef = newSuperTypeRef
+    }
+
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirElement {
         superTypeRef = superTypeRef.transformSingle(transformer, data)
         return this