Implement jfieldID and jmethodID properly.

Change-Id: I048107fbca4e21cf34e8fda6defdbc0b97421cf0
diff --git a/src/object.h b/src/object.h
index c78103b..2b5a054 100644
--- a/src/object.h
+++ b/src/object.h
@@ -979,6 +979,20 @@
     return num_reference_instance_fields_;
   }
 
+  // Finds the given instance field in this class or a superclass.
+  Field* FindInstanceField(const StringPiece& name,
+      const StringPiece& descriptor);
+
+  Field* FindDeclaredInstanceField(const StringPiece& name,
+      const StringPiece& descriptor);
+
+  // Finds the given static field in this class or a superclass.
+  Field* FindStaticField(const StringPiece& name,
+      const StringPiece& descriptor);
+
+  Field* FindDeclaredStaticField(const StringPiece& name,
+      const StringPiece& descriptor);
+
   Field* GetInstanceField(uint32_t i) const {  // TODO: uint16_t
     DCHECK_NE(NumInstanceFields(), 0U);
     return ifields_->Get(i);