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

This pulls in the following LLVM changes:

77fc541: (dschuff@chromium.org) PNaCl ABI: add passes to cleanup/finalize some linkage types and resolve aliases.
9c7984e: (mseaborn@chromium.org) PNaCl: Add ExpandGetElementPtr pass for converting GetElementPtr to arithmetic

BUG=none
TEST=PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/12984019

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@11071 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client