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

This pulls in the following Clang change:

25662b2: (phosek@chromium.org) Cherry-pick upstream r237073

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4333
TEST= PNaCl toolchain trybots
R=dschuff@chromium.org

Review URL: https://codereview.chromium.org/1436063002 .

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