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

This pulls in the following LLVM change:

2a2ca21: (jvoung@chromium.org) Link LLVM bitcode reader into the sandboxed PNaCl for debug support.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3765
TEST= PNaCl toolchain trybots
R=jfb@chromium.org

Review URL: https://codereview.chromium.org/194613006

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@12874 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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