[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 85b5315 [InstSimplify] Fold abs(abs(x)) -> abs(x)
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   85b5315..e297d92  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to e297d928dcde31ac92eff72532095f4f657f2ebd.
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!