[krbdev.mit.edu #7860] libdb2 tests hang

[Greg Hudson via RT]

Thanks for the additional investigation.  I reproduce the test2 recno 
hang using gcc 4.8.1 and -O2.  I will try to narrow it down.  It isn't 
necessarily the compiler's fault; the code could be using an undefined 
behavior.

(My regular dev machine uses gcc 4.6.3 and doesn't exhibit the problem at 
any optimization level.  This is consistent with Pierre's findings.)