Check nullability in initial constraints

except constraints for receiver type (it can be accessed via safe call)

compiler/testData/diagnostics/tests/incompleteCode/checkNothingIsSubtype.kt

@@ -6,7 +6,7 @@ interface A<T>
 fun <T> infer(<!UNUSED_PARAMETER!>a<!>: A<T>) : T {<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>
 
 fun test(nothing: Nothing?) {
-    val <!UNUSED_VARIABLE!>i<!> = <!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>infer<!>(<!TYPE_MISMATCH!>nothing<!>)
+    val <!UNUSED_VARIABLE!>i<!> = <!TYPE_INFERENCE_INCORPORATION_ERROR!>infer<!>(<!TYPE_MISMATCH!>nothing<!>)
 }
 
 fun sum(<!UNUSED_PARAMETER!>a<!> : IntArray) : Int {