[FIR] KT-57095: Allow X? -> * assignments in unification

^KT-57095 Fixed

Merge-request: KT-MR-9180
Merged-by: Nikolay Lunyak <Nikolay.Lunyak@jetbrains.com>

compiler/testData/diagnostics/tests/rawCastToStarProjection_Fail.kt

@@ -0,0 +1,9 @@
+// FIR_IDENTICAL
+// ISSUE: KT-57095
+
+open class ValueType<T> {
+    class Optional<T>: ValueType<T?>()
+}
+private fun checkType(type: ValueType<*>) {
+    type as ValueType.Optional // K1: ok, K2: NO_TYPE_ARGUMENTS_ON_RHS
+}