[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at fde8351 [AMDGPU] Fix lowering of S_MOV_{B32,B64}_term
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   fde8351..d93287c  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d93287cac89fd50a105ac4a59c079884b8e53e49.
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!