[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 44b1643 [NewPM] Support -disable-simplify-libcall/-disable-builtin in NPM opt
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   44b1643..0b9f9ec  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 0b9f9eced9c532ee9bbf320216a2e85b314eb5f0.
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!