[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ae20939 [OpenMP] Begin Printing Information Dumps In Libomptarget and Plugins
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ae20939..ba5b137  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to ba5b1371ecc575337a95e9a9fc2b8951dae73aab.
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!