[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 6a06c7a [X86] isHorizontalBinOp - only update LHS/RHS references on success
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   6a06c7a..0ccda7c  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 0ccda7c2326e1dc4e0d5d601dcc06c4b576acb0e.
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!