[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ef0ab3c [InstCombine] Fix typo in narrow funnel shift test
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ef0ab3c..13410fa  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 13410fa79ff0176fd111b8e3e1ea64c54bc7fea1.
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!