[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 3945b69 [SVE][CodeGen] Replace more TypeSize comparison operators with their scalar equivalents
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   3945b69..8a7ca14  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 8a7ca143f8bdc92824d949374c7e9ee9b33fb6af.
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!