DERBY-6206: Cleanup mutability problems in org.apache.derby.impl.jdbc.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1476983 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6206: Cleanup some mutability problems in the rg.apache.derby.impl.sql package.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1477222 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6206: Cleanup mutability problem in GenericResultDescription.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1477320 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6169: Reduce visibility of classes and methods under impl/sql

- Make all fields of CreateViewNode and BasicProviderInfo private.

- Make BasicProviderInfo's constructor package private.

- Make CreateViewNode.getProviderInfo() return an immutable list
  instead of the actual array to prevent accidental modification by
  the caller.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1477476 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6169: Reduce visibility of classes and methods under impl/sql

Remove two unused methods in the TriggerExecutionContext interface,
and their implementations in InternalTriggerExecutionContext. This
also made it possible to remove some fields that were only used by the
removed methods, and also corresponding fields and parameters in
neighbour classes.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1477477 13f79535-47bb-0310-9956-ffa450edef68