ART: Add GetClassVersionNumbers.

Add support for GetClassVersionNumbers. Return the dex file version
as major, zero as minor. Add test.

Bug: 31684578
Test: m test-art-host-run-test-912-classes
Change-Id: Ib5082cd58b27a9183d8f19d42d4d8af46a6bb9c9
diff --git a/test/912-classes/src/Main.java b/test/912-classes/src/Main.java
index ea3c49c..cbf2392 100644
--- a/test/912-classes/src/Main.java
+++ b/test/912-classes/src/Main.java
@@ -80,6 +80,10 @@
     testClassLoader(getProxyClass());
 
     testClassLoaderClasses();
+
+    System.out.println();
+
+    testClassVersion();
   }
 
   private static Class<?> proxyClass = null;
@@ -202,6 +206,10 @@
     }
   }
 
+  private static void testClassVersion() {
+    System.out.println(Arrays.toString(getClassVersion(Main.class)));
+  }
+
   private static void printClassLoaderClasses(ClassLoader cl) {
     for (;;) {
       if (cl == null || !cl.getClass().getName().startsWith("dalvik.system")) {
@@ -262,6 +270,8 @@
 
   private static native Class<?>[] getClassLoaderClasses(ClassLoader cl);
 
+  private static native int[] getClassVersion(Class<?> c);
+
   private static class TestForNonInit {
     public static double dummy = Math.random();  // So it can't be compile-time initialized.
   }