CORBA24 — Expected behavior of POA configured with ServantLocator receiving LocateRe

Summary: This is an issue with the Portable Object Adapter:

If a POA configured with a ServantLocator receives a LocateRequest, what
is the expected behavior? A ServantLocator expects to receive an operation
name as a parameter to preinvoke() and postinvoke(), but there is no
operation name in a LocateRequest.

We could just return a true response to the LocateRequest and not involve
the ServantLocator. That might mislead the sender though. If the sender
received a true response and then sent a message they might get an
OBJECT_NOT_EXIST exception back.

We could pass an operation name like "_locate" to the manager. That would
let the manager know that a location request was being processed, and the
underscore would signify that it is an internal message since it"s not a
_get or _set.

Add a subsection to section 11.3.6 specifying "_locate" and its usage.