[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f5fa5b9 [scudo/standalone] Fix undefined behavior in checksum test
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f5fa5b9..f4e5541  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to f4e554180962aa6bc93678898b6933ea712bde50.
CMake Error at CMakeLists.txt:3 (cmake_minimum_required):
  CMake 3.13.4 or higher is required.  You are running version 3.7.1


-- Configuring incomplete, errors occurred!