Update PNaCL LLVM REV.
Update PNaCL LLVM REV.

a4c38e6 Copy llvm-bcanalyzer to build pnacl-bcanalyzer.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3405
Review URL= https://codereview.chromium.org/15013003

R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/14885009

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@11304 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

Lind-Project/native_client,Lind-Project/native_client,Lind-Project/native_client,Lind-Project/native_client,Lind-Project/native_client,Lind-Project/native_client