[NI] Infer type variable to Nothing if all upper constraints are from upper bounds

#KT-32196 Fixed

compiler/testData/diagnostics/tests/inference/kt32196.fir.kt

@@ -0,0 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class Inv<T>
+
+fun <R : Any> Inv<Int>.mapNotNull(transform: (Int) -> R?): Inv<R> = null!!
+
+fun test(inv: Inv<Int>) {
+    inv.mapNotNull { null }
+}