[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at b289dc5 [CVP] Narrow SDiv/SRem to the smallest power-of-2 that's sufficient to contain its operands
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   b289dc5..b89059a  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b89059a31347dd09b55a96b99b3dbe38d7749908.
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!