Start implementing jdb "locals".

This lets us show the names and types of the locals, but all the values
will show up as 0/null. We're going to have to walk the whole stack and
take callee-save frames into account to do that right.

Change-Id: Ic6e115513b6e65ae7ed4b7274e70bc514e83190a
diff --git a/src/oatdump.cc b/src/oatdump.cc
index 8b0ada4..2d5732f 100644
--- a/src/oatdump.cc
+++ b/src/oatdump.cc
@@ -315,7 +315,7 @@
       StringAppendF(&summary, "FIELD %s", PrettyField(field).c_str());
     } else if (obj->IsArrayInstance()) {
       StringAppendF(&summary, "ARRAY %d", obj->AsArray()->GetLength());
-    } else if (obj->IsString()) {
+    } else if (obj->GetClass()->IsStringClass()) {
       StringAppendF(&summary, "STRING %s", obj->AsString()->ToModifiedUtf8().c_str());
     } else {
       StringAppendF(&summary, "OBJECT");