[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 8b6d1c0 [ADT] Use alignas + sizeof for inline storage, NFC
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   8b6d1c0..94c18d9  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 94c18d91d24355ba7274c4f40f3e8754a5f72c41.
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!