[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 98aa067 [Syntax] Start to move trivial Node class definitions to TableGen. NFC
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   98aa067..04ce13e  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 04ce13e497be60f51d340e649c72138d49cb13e9.
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!