[FIR] Add REDUNDANT_NULLABLE diagnostics

compiler/testData/diagnostics/tests/ProjectionsInSupertypes.fir.kt

@@ -1,6 +1,7 @@
+// WITH_EXTENDED_CHECKERS
 interface A<T> {}
 interface B<T> {}
 interface C<T> {}
 interface D<T> {}
 
-interface 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!>?<!>, D<Int> {}
+interface 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!>*<!>>?<!REDUNDANT_NULLABLE!>?<!NULLABLE_SUPERTYPE!>?<!><!>, D<Int> {}

compiler/testData/diagnostics/tests/cast/bare/RedundantNullable.fir.kt

@@ -1,4 +0,0 @@
-interface B<T>
-class G<T>: B<T>
-
-fun f(b: B<String>?) = b is G??

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

@@ -1,3 +1,5 @@
+// FIR_IDENTICAL
+// WITH_EXTENDED_CHECKERS
 interface B<T>
 class G<T>: B<T>
 

compiler/testData/diagnostics/tests/nullableTypes/baseWithNullableUpperBound.fir.kt

@@ -1,13 +0,0 @@
-fun <NN: Any, NNN: NN> nonMisleadingNullable(
-        nn: NN?,
-        nnn: NNN?
-) {}
-
-fun <T, N: T, INDIRECT: N> misleadingNullableSimple(
-        t: T?,
-        t2: T?,
-        n: N?,
-        ind: INDIRECT?
-) {}
-
-fun <T> interactionWithRedundant(t: T??) {}

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

@@ -1,3 +1,5 @@
+// FIR_IDENTICAL
+// WITH_EXTENDED_CHECKERS
 fun <NN: Any, NNN: NN> nonMisleadingNullable(
         nn: NN?,
         nnn: NNN?

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

@@ -1,9 +1,10 @@
+// WITH_EXTENDED_CHECKERS
 class Generic<T>
 
 fun redundantNullable(
-        i: Int??,
-        three: Int???,
-        gOut: Generic<Int>??,
-        gIn: Generic<Int??>
+        i: Int?<!REDUNDANT_NULLABLE!>?<!>,
+        three: Int?<!REDUNDANT_NULLABLE!>??<!>,
+        gOut: Generic<Int>?<!REDUNDANT_NULLABLE!>?<!>,
+        gIn: Generic<Int?<!REDUNDANT_NULLABLE!>?<!>>
 ) {
 }

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

@@ -1,9 +1,10 @@
+// WITH_EXTENDED_CHECKERS
 interface A
-interface X: A?<!NULLABLE_SUPERTYPE!>?<!> {
+interface X: A?<!NULLABLE_SUPERTYPE, REDUNDANT_NULLABLE!>?<!> {
 
 }
 
 fun <T> interaction(t: T) {
     if (t == null) {}
 
-}
+}

compiler/testData/diagnostics/tests/typealias/kt15734.fir.kt

@@ -1,19 +0,0 @@
-@Target(AnnotationTarget.TYPE)
-annotation class Ann
-
-typealias TString = String
-
-typealias TNString = TString?
-
-typealias TNAString = @Ann TString?
-
-val test1: TNString = TODO()
-val test2: TNAString = TODO()
-val test3: List<TNString> = TODO()
-val test4: List<TNAString> = TODO()
-val test5: List<TNString?> = TODO()
-val test6: () -> List<TNString> = TODO()
-
-fun test(x: TNString) {
-    x<!UNSAFE_CALL!>.<!>hashCode()
-}

compiler/testData/diagnostics/tests/typealias/kt15734.kt

@@ -1,3 +1,5 @@
+// FIR_IDENTICAL
+// WITH_EXTENDED_CHECKERS
 @Target(AnnotationTarget.TYPE)
 annotation class Ann