Many duplicate bugs are filed against the compiler, only because the compiler
asks the user to file a bug report:

"An error has occurred in the compiler...please file a bug report."

It would be useful to encourage users to check the JDC Bug Parade (for dupes)
before filing a "new" bug report.

Since JDK licensees may prefer to provide their own equivalent of such a
message, perhaps we could provide a "hook" for including the message.

Alternatively, we can simply add more filtering to our bug-processing tools
(i.e., Incident Manager), to pre-filter such duplicate reports as much as
possible.