Hi,

V8->V9
- rebase on top of Hannes's patch in the same area [1]
- no changes to patches 1 and 2
- added patches 3 and 4 as RFC to address Daniel's concern.
  patch 3 moves eBPF instruction macros and
  patch 4 split macros which are shared between classic and eBPF
  into bpf_common.h
  3 and 4 will be used by verifier testsuite and will be reposted later
  during stage III

V8 thread with 'why' reasoning and end goal:
https://lkml.org/lkml/2014/8/27/628

Original set [2] of ~28 patches I'm planning to present in 4 stages:

  I. this 2 patches to fork off llvm upstreaming
 II. bpf syscall with manpage and map implementation
III. bpf program load/unload with verifier testsuite (1st user of
     instruction macros from bpf.h and 1st user of load imm64 insn)
 IV. tracing, etc

[1] http://patchwork.ozlabs.org/patch/385266/
[2] https://lkml.org/lkml/2014/8/26/859