[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 655923de [macho2yaml][test] Specify the object file's endianness. NFC.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   655923de..a542eec master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to a542eec4622c62bdb7b35d8f6dae7560f581ba50.
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!