[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 61ac58e [NewPM] Pin tests with -debug-pass to legacy PM
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   61ac58e..2d0de5f  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 2d0de5f9a4c58e2fcdd8f00dabca505ba47abbd0.
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!