[dmd-internals] Some help for fixing Bug6189

[Martin Nowak]

I could use some help in fixing this bug.
http://d.puremagic.com/issues/show_bug.cgi?id=6189

So if anybody who has some understanding of register handling in the  
backend
could help pinpointing the point of infection for this bug, that would be  
great.
If there really is not a single point of failure, comments on the proposed  
improvements (see #6189)
would also help.

martin