[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at b34f116 [flang] Fix assert on constant folding of extended types
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   b34f116..0448d11  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 0448d11a06b451a63a8f60408fec613ad24801ba.
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!