[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at a8a8516 Revert "[Asan] Accept __lsan_ignore_object for redzone pointer"
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   a8a8516..cb1ef0e  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to cb1ef0eaff8726a8c1fe4b8440f6734cbbe91630.
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!