Same "LLVM ERROR: ran out of registers during register allocation" here when
running Brutal Legend from Steam.  The crash doesn't happen until part way
through the loading screen when loading a save.  Works fine in the main menus. 
This game was working before when I had an nvidia gtx260 card, but crashes now
that I have switched to radeon hd 7850.  

Software:
Kernel 3.13.6
Mesa 10.0.3
Xen 4.3.1 (running under dom0)

Hardware:
Intel i7 3770
AMD Radeon HD 7850: 01:00.0 VGA compatible controller: Advanced Micro Devices,
Inc. [AMD/ATI] Pitcairn PRO [Radeon HD 7850]

I will upgrade to the latest versions available in Arch this weekend to see if
mesa 10.1 / linux 3.13 fixes it.  If not, I'll attempt git versions.