[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at b1c1825 [X86] Remove unused argument from HandleAVX512Operand in the assembly parser.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   b1c1825..926c147  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 926c14798d317a8c60592f420bb79cd80c150285.
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!