[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at abaa870 Add x86 REQUIRES to tests from 2c5f3d54c5ee / D85746
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   abaa870..3fcca80  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 3fcca804b2916b68d34523e9f88c77272a256d77.
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!