[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 39108f4 ARM: make Thumb1 instructions non-flag-setting in IT block.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   39108f4..bd93f5c  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to bd93f5ce07ef2fb9c1897bddc576fe4afb464788.
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!