[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at a8b8a93 [llvm-profdata]Fix llvm-profdata crash on compact binary profile
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   a8b8a93..d0648568 master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d06485685d421c944afeffc3ad59f6f6f78afd72.
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!