FIR: improve inference of implicit type arguments in casts

Type parameters do not necessarily match one-to-one, or preserve order.

compiler/testData/diagnostics/tests/cast/bare/NullableAsNullableNotEnough.fir.kt

@@ -4,6 +4,6 @@ interface Tr
 interface G<T>
 
 fun test(tr: Tr?) {
-    val v = tr as G?
-    checkSubtype<G<*>>(v!!)
+    val v = tr as <!WRONG_NUMBER_OF_TYPE_ARGUMENTS!>G?<!>
+    <!INAPPLICABLE_CANDIDATE!>checkSubtype<!><G<*>>(v!!)
 }