[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d50d4c3 [Hexagon] Correct the order of operands when lowering funnel shift-left
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d50d4c3..60c889c  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 60c889cf714cd9488b1a54482b64948dd21a4d5f.
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!