PNaCl: Update LLVM revision in pnacl/DEPS
PNaCl: Update LLVM revision in pnacl/DEPS

This pulls in the following LLVM changes:

2228738: (mseaborn@chromium.org) PNaCl wire format: Remove function attributes from pexe reader/writer
9c2f4c4: (eliben@chromium.org) Update LangRef.rst to the 3.3 version and add PnaclRef.rst
7001e7a: (mseaborn@chromium.org) PNaCl wire format: Update comments for function attribute removal

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3506
TEST=PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/17257005

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@11597 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