[RFC] jscript: Fix shift/reduce conflict by removing redundant FunctionDeclaration rule.

[Jacek Caban]

Rob Shearman wrote:
>  Jacek, are you OK with deviating from the specification like this?
>   

Sure, I was thinking about something like this when I was writing the 
parser, but I decided that it's better to stick with documentation then 
to get something working. Now that we have tests and we may test it on 
real applications (Photoshop installers are good tests), we may clean it 
up IMO.

Jacek