Fix diagnostic inferred type calculation for null in some cases

#KT-36222 fixed

compiler/testData/diagnostics/tests/regressions/kt36222.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun foo(f: () -> String) {}
+fun <K> select(x: K, y: K): K = x
+
+fun test() {
+    foo { <!TYPE_MISMATCH!>select("non-null", null)<!> } // inferred String? but String is expected
+}
+