[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 92bca12 [AIX] add new option -mignore-xcoff-visibility
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   92bca12..7238faa  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 7238faa4ae977523903192e287d442eb53c49ee5.
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!