ART: Add GetClassLoader

Add support for GetClassLoader. Add a test.

Bug: 31684578
Test: m test-art-host-run-test-912-classes
Change-Id: I629ec2a1f4843bc3b28e40111805e250be44d993
diff --git a/runtime/openjdkjvmti/OpenjdkJvmTi.cc b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
index d17376b..175dca2 100644
--- a/runtime/openjdkjvmti/OpenjdkJvmTi.cc
+++ b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
@@ -602,7 +602,7 @@
   }
 
   static jvmtiError GetClassLoader(jvmtiEnv* env, jclass klass, jobject* classloader_ptr) {
-    return ERR(NOT_IMPLEMENTED);
+    return ClassUtil::GetClassLoader(env, klass, classloader_ptr);
   }
 
   static jvmtiError GetSourceDebugExtension(jvmtiEnv* env,