Graphite review, graphite parts [1/n]

[Sebastian Pop]

> Why are you doing all this virtual-phi stuff?  Why are you not just
> renaming all symbols that appear in virtual operands?

This is the last part of the review comments.  We are working on
addressing this in a patch that cleans up the code generator.

I will diff again the graphite branch against trunk and prepare the
split patches such that it will be simpler for you to review all the
changes.

Sebastian