JetDiagnosticsTest migrated to TestGenerator

- test data files renamed from *.jet to *.kt

compiler/testData/diagnostics/tests/scopes/kt323.kt

@@ -0,0 +1,18 @@
+//KT-323 Handle visibility interactions with overriding
+package kt323
+
+open class A {
+    open var a : Int = 0
+}
+
+class B : A() {
+    override <!VAR_OVERRIDDEN_BY_VAL!>val<!> a = 34
+
+    var b : Int
+        <!GETTER_VISIBILITY_DIFFERS_FROM_PROPERTY_VISIBILITY!>public<!> get() = 23
+        set(i: Int) {}
+
+    protected var c : Int
+        get() = 23
+        private set(i: Int) {}
+}