[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at e53196b [X86] Add support for calling SimplifyDemandedBits on the input of PDEP with a constant mask.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   e53196b..e72d792  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to e72d792c147ee506e337401e20c0f23042cc43fe.
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!