ART: Add GetMethodDeclaringClass

Support GetMethodDeclaringClass to retrieve the declaring class
of a JNI method.

Extend test 910. Also cover proxies.

Bug: 31684812
Test: m test-art-host-run-test-910-methods
Change-Id: I8508f96f88692e540ef53f693ff85590b7553f19
diff --git a/runtime/openjdkjvmti/ti_method.h b/runtime/openjdkjvmti/ti_method.h
index 17a3728..7cae0bf 100644
--- a/runtime/openjdkjvmti/ti_method.h
+++ b/runtime/openjdkjvmti/ti_method.h
@@ -44,6 +44,10 @@
                                   char** name_ptr,
                                   char** signature_ptr,
                                   char** generic_ptr);
+
+  static jvmtiError GetMethodDeclaringClass(jvmtiEnv* env,
+                                            jmethodID method,
+                                            jclass* declaring_class_ptr);
 };
 
 }  // namespace openjdkjvmti