[TEST] Migrate duplicating javac tests to new test runners

Also minimize scope of DiagnosticUsingJavac tests to
 `compiler/testData/diagnostics/tests/javac`. This is fine since
 javac compilation mode is still not finished and no one not going to
 support it

compiler/testData/diagnostics/tests/javac/inheritance/ManyInheritedClasses.kt

@@ -0,0 +1,44 @@
+// FIR_IDENTICAL
+// FILE: a/x.java
+package a;
+
+public interface x {
+
+    public class d {}
+
+    public class z {}
+
+    public class o {}
+}
+
+// FILE: a/b.java
+package a;
+
+public interface b extends x {
+
+    public class y {}
+
+}
+
+// FILE: a/c.java
+package a;
+
+public class c implements x {
+
+    public class d {}
+
+}
+
+// FILE: a/f.java
+package a;
+
+public class f extends c implements b {
+
+    public class o {}
+
+    public d getD() { return null; }
+    public y getY() { return null; }
+    public z getZ() { return null; }
+    public o getO() { return null; }
+
+}