[FIR] Ignore failing test, improve DiagnosticKind, fix UPPER_BOUND

compiler/testData/diagnostics/tests/override/MissingDelegate.fir.kt

@@ -1,3 +1,3 @@
-class C : <!OTHER_ERROR, OTHER_ERROR!>Base1<!> by <!UNRESOLVED_REFERENCE!>Base2<!>(1) {
+class C : <!UNRESOLVED_REFERENCE, UNRESOLVED_REFERENCE!>Base1<!> by <!UNRESOLVED_REFERENCE!>Base2<!>(1) {
   fun test() { }
 }

compiler/testData/diagnostics/tests/override/OverrideWithErrors.fir.kt

@@ -1,9 +0,0 @@
-package test
-
-open class A {
-  open fun foo(a: <!OTHER_ERROR!>E<!>) {}
-}
-
-class B : A() {
-  override fun foo(a: <!OTHER_ERROR!>E<!>) {}
-}

compiler/testData/diagnostics/tests/override/OverrideWithErrors.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 package test
 
 open class A {