llvm_tools: add a file to contain llvm testing information

This will be the new home for the LLVM_NEXT SHA (and associated
revision).

BUG=b:333462347
TEST=Unittests

Change-Id: Ic03420e5c201a826c3cebdb79f900cceb91e6dc3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/5450239
Reviewed-by: Jordan Abrahams-Whitehead <ajordanr@google.com>
Tested-by: George Burgess <gbiv@chromium.org>
Commit-Queue: George Burgess <gbiv@chromium.org>
2 files changed