[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d0abc75 [GlobalISel] Disable the indexed loads combine completely unless forced. NFC.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d0abc75..b2e27a8  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to b2e27a86c18e13043be0ed7bf2855d313cc0ac38.
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!