DERBY-5546(ResultSet#updateBigDecimal on a REAL column does not do underflow checking)

Backporting to 10.9

Fix provided by Dag Wanvik



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.9@1511185 13f79535-47bb-0310-9956-ffa450edef68