Fixing a subtle bug in receiver resolution when a thrown and caught function ...

Fixing a subtle bug in receiver resolution when a thrown and caught function is called from a catch-block.
Second attempt - now with better memory efficiency.

Committed: http://code.google.com/p/v8/source/detail?r=999

[Mads Ager (chromium), 2008-12-18 10:00:32]

Overall, this looks like the right approach.  Adding another field to all
contexts seems like a lot of overhead to solve this problem though.  How about
adding another map only used for 'catch' contexts?  Then we know when resolving
the receiver if the context is a 'catch' context and in that case the with
object can be extracted from the scope chain and we don't have to store it
explicitly?

[Mads Ager (chromium), 2008-12-18 10:10:29]

Does this work if you assign to the catch variable inside of the catch block? 
Adding tests of that behavior would be good too.

[Mads Ager (chromium), 2008-12-18 10:45:22]

LGTM