[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f48eced [XCOFF] emit .rename for .lcomm when necessary
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f48eced..c466c5f  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to c466c5fa7ee90f90c0e1d08777f1f085bb78a475.
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!