NB 7.2 HR integration request: #182009 - Runtime error occured due to Uncompilable source code

Description:
http://netbeans.org/bugzilla/show_bug.cgi?id=182009

Having "Compile On Save" turned on, the "Uncompilable source code" 
runtime exception happens sometime even though no compilation errors are 
reported.

Risk assessment: low.

The patch is reviewed by Jan Lahoda and verified by Jirka Prox.

Changesets:
http://hg.netbeans.org/main/nb-javac/rev/2556fa58461e
http://hg.netbeans.org/jet-main/rev/1f73b5c2a68c

Thanks for review,
Dusan