[patch]: make idata$4 and .idata$5 more compliant to coff spec

[Nick Clifton]

Hi Kai,

> Ok, how should I name it?
> For dlltool maybe the option --prefixed-import-tables and same for ld?

Using the same name for both tools is a good idea.  I would suggest a 
slightly more informative name though.  How about 
--use-nul-prefixed-import-tables ?

Cheers
   Nick