JetDiagnosticsTest migrated to TestGenerator

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

compiler/testData/diagnostics/tests/j+k/StaticMembersFromSuperclasses.kt

@@ -0,0 +1,16 @@
+// FILE: Aaa.java
+// http://youtrack.jetbrains.com/issue/KT-1880
+
+public class Aaa {
+    public static final int i = 1;
+}
+
+// FILE: Bbb.java
+
+public class Bbb extends Aaa {
+    public static final String i = "s";
+}
+
+// FILE: b.kt
+
+fun foo() = Bbb.i