[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d4e81cd [Tests][LoopVect] Exercise basic uniform memory operand logic
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d4e81cd..a4124e4  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to a4124e455e641db1e18d4221d2dacb31953fd13b.
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!