Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/constructors/allCallsPrimary.java

@@ -0,0 +1,21 @@
+//file
+class C {
+  C(int arg1, int arg2, int arg3) {
+  }
+
+  C(int arg1, int arg2) {
+    this(arg1, arg2, 0);
+  }
+
+  C(int arg1) {
+    this(arg1, 0, 0);
+  }
+}
+
+public class User {
+  public static void main() {
+     C c1 = new C(100, 100, 100);
+     C c2 = new C(100, 100);
+     C c3 = new C(100);
+  }
+}