replay fixes for value type reference fields

[Roland Westrelin]

http://cr.openjdk.java.net/~roland/valhalla/replay-reffields/webrev.00/

This should fix compilation replay so it handles reference fields in
static value type fields. It also improves replay a bit: for object
fields, replay dumps the signature of the field which could differ from
the actual field type. An field declared as Object could even be an
array.. With that change replay dumps the actual field type.

Roland.