Cleanup of redefinition testing

Move redefine logic into a single common function and perform some
other cleanup.

Test: mma -j40 test-art-host
Change-Id: I8618bda4f392b683ce198374066e356b87578e7b
diff --git a/runtime/openjdkjvmti/transform.h b/runtime/openjdkjvmti/transform.h
index 35b990b..0ad5099 100644
--- a/runtime/openjdkjvmti/transform.h
+++ b/runtime/openjdkjvmti/transform.h
@@ -41,6 +41,8 @@
 
 namespace openjdkjvmti {
 
+jvmtiError GetClassLocation(ArtJvmTiEnv* env, jclass klass, /*out*/std::string* location);
+
 // Gets the data surrounding the given class.
 jvmtiError GetTransformationData(ArtJvmTiEnv* env,
                                  jclass klass,