[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at db1988f [ELF] Don't change binding to STB_WEAK for an undefined specified by -u
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   db1988f..19d6413  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 19d64138e6a708d1d0571da3ac51e1b4777c2b47.
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!