[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f8454d6 [AIX][compiler-rt][builtins] Don't add ppc builtin implementations that require __int128 on AIX
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f8454d6..21a008b  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 21a008bbba74eeda3e8f271c3bba907387621a6e.
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!