A warning for redundant '?' in types

compiler/testData/diagnostics/tests/ProjectionsInSupertypes.kt

@@ -3,4 +3,4 @@ trait B<T> {}
 trait C<T> {}
 trait D<T> {}
 
-trait Test : A<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>in<!> Int>, B<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>out<!> Int>, C<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>*<!>><!NULLABLE_SUPERTYPE!>?<!><!NULLABLE_SUPERTYPE!>?<!><!NULLABLE_SUPERTYPE!>?<!>, D<Int> {}
+trait Test : A<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>in<!> Int>, B<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>out<!> Int>, C<<!PROJECTION_IN_IMMEDIATE_ARGUMENT_TO_SUPERTYPE!>*<!>><!NULLABLE_SUPERTYPE!>?<!><!REDUNDANT_NULLABLE!>?<!><!REDUNDANT_NULLABLE!>?<!>, D<Int> {}

compiler/testData/diagnostics/tests/nullableTypes/redundantNullable.kt

@@ -0,0 +1,9 @@
+class Generic<T>
+
+fun redundantNullable(
+        <!UNUSED_PARAMETER!>i<!>: Int?<!REDUNDANT_NULLABLE!>?<!>,
+        <!UNUSED_PARAMETER!>three<!>: Int?<!REDUNDANT_NULLABLE!>?<!><!REDUNDANT_NULLABLE!>?<!>,
+        <!UNUSED_PARAMETER!>gOut<!>: Generic<Int>?<!REDUNDANT_NULLABLE!>?<!>,
+        <!UNUSED_PARAMETER!>gIn<!>: Generic<Int?<!REDUNDANT_NULLABLE!>?<!>>
+) {
+}

compiler/testData/diagnostics/tests/nullableTypes/redundantNullableInSupertype.kt

@@ -0,0 +1,8 @@
+trait X: Any<!NULLABLE_SUPERTYPE!>?<!><!REDUNDANT_NULLABLE!>?<!> {
+
+}
+
+fun interaction<T>(t: T) {
+    if (<!SENSELESS_COMPARISON!>t == null<!>) {}
+
+}