[FE 1.0] Implement deprecation warning for private constructors of sealed classes

^KT-44866
^KT-49729 Fixed

compiler/testData/diagnostics/tests/sealed/privateSealedConstructors_warning.kt

@@ -0,0 +1,21 @@
+// LANGUAGE: -UseConsistentRulesForPrivateConstructorsOfSealedClasses
+// ISSUE: KT-44866, KT-49729
+
+// FILE: base.kt
+sealed class SealedBase(x: Int) {
+    private constructor(y: String) : this(y.length)
+
+    class SealedNested : SealedBase("nested")
+}
+class SealedOuter : <!RESOLUTION_TO_PRIVATE_CONSTRUCTOR_OF_SEALED_CLASS!>SealedBase<!>("outer")
+
+abstract class RegularBase(x: Int) {
+    private constructor(y: String) : this(y.length)
+
+    class RegularNested : RegularBase("nested")
+}
+class RegularOuter : <!INVISIBLE_MEMBER!>RegularBase<!>("outer")
+
+// FILE: derived.kt
+
+class SealedOuterInDifferentFile : <!INVISIBLE_MEMBER, RESOLUTION_TO_PRIVATE_CONSTRUCTOR_OF_SEALED_CLASS!>SealedBase<!>("other file")