c/7344: performance regression on huge case statements

[Nathanael Nerode]

What should we do for a test case here?  I feel that it should have one,
but the minimal testcase is *inherently* 239K, so I'm not quite sure 
what to do here.

I guess ideally the testcase would generate a giant case statement, try 
to compile it, and kill the process if it took longer than (x) seconds. 
  This is completely out of the normal test scheme however.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7344