FE 1.0: introduce deprecation for Enum.declaringClass (KT-49653)

compiler/testData/diagnostics/tests/enum/declaringClass.kt

@@ -1,9 +1,10 @@
 // FULL_JDK
 // WITH_STDLIB
+// !LANGUAGE: -ProhibitEnumDeclaringClass
 
 import java.util.*
 
 fun <E : Enum<E>> foo(values: Array<E>) {
-    EnumSet.noneOf(values.first().declaringClass)
+    EnumSet.noneOf(values.first().<!ENUM_DECLARING_CLASS_DEPRECATED_WARNING!>declaringClass<!>)
     EnumSet.noneOf(values.first().<!UNRESOLVED_REFERENCE!>getDeclaringClass<!>())
 }