[PATCH] Debug info: Support fragmented variables.

[Eric Christopher]

  Let's look into splitting this up and out a bit. I think being able to have complex addresses as part of a location in the debug value instruction should be fine. The multiple optional statements bother me a bit, I guess we'll need to add a null metadata in cases where you want to use this. What about turning it into a non-optional argument? Just keep a NULL for a complex address? How badly does that affect the existing tests?

  Let's split the patch out with just the infrastructure changes needed and a testcase to use them and we'll go from there? In general, I think it's a good idea, just a big patch :)

  i'd probably split out the "optimize" as well. Yeah, we'll emit non-optimal for a couple of patches, but as an add-on that seems like a more obvious patch.

  I echo Chandler's thoughts about the type uniquing map. What's going on there?

http://reviews.llvm.org/D2680