[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at cdd339c [InstCombine] PHI-of-insertvalues -> insertvalue-of-PHI's
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   cdd339c..3ff4d75  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 3ff4d75c9cbffb12c5c690c389e3977ea6811042.
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!