[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at a4124e4 [X86] When storing v1i1/v2i1/v4i1 to memory, make sure we store zeros in the rest of the byte
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   a4124e4..b940612  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b9406121a04eb04069b58815185f6da4ee22b455.
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!