[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 93a1fc2 Try to fix build. May have used a C++ feature too new/not supported on all platforms.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   93a1fc2..196c097  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 196c097bba8b0b3932f3fcdcd5310f78ebaa43a3.
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!