[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.

  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 :)

  -eric

http://llvm-reviews.chandlerc.com/D2680