[PATCH] Implement Named Register Global Variables in LLVM

[Renato Golin]

Good point. I'll add some negative tests.

About the non-allocatable registers, to be fair, the *only* register that is accepted right now is the stack pointer. Should I add to each architecture the list of non-allocatable ones, too? Or should I just update the docs saying that, for now, only the stack pointer works?

http://reviews.llvm.org/D3261