Make PrettyMethod note when a method is obsolete

This should make debugging issues surrounding obsolete methods easier.

Test: ./test.py --host -j72
Change-Id: I347037eb77fe9790a99ff9cd5f87faeb795d2ee2
diff --git a/runtime/art_method.cc b/runtime/art_method.cc
index 882291f..5f5361a 100644
--- a/runtime/art_method.cc
+++ b/runtime/art_method.cc
@@ -814,7 +814,12 @@
   }
   ArtMethod* m =
       GetInterfaceMethodIfProxy(Runtime::Current()->GetClassLinker()->GetImagePointerSize());
-  return m->GetDexFile()->PrettyMethod(m->GetDexMethodIndex(), with_signature);
+  std::string res(m->GetDexFile()->PrettyMethod(m->GetDexMethodIndex(), with_signature));
+  if (with_signature && m->IsObsolete()) {
+    return "<OBSOLETE> " + res;
+  } else {
+    return res;
+  }
 }
 
 std::string ArtMethod::JniShortName() {