Do not allow inference of type arguments on the rhs if there's no information available

compiler/testData/diagnostics/tests/cast/bare/NullableAsNotEnough.kt

@@ -0,0 +1,7 @@
+trait Tr
+trait G<T>
+
+fun test(tr: Tr?) {
+    val v = tr as <!NO_TYPE_ARGUMENTS_ON_RHS!>G<!>
+    v: G<*>
+}