[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at f6fa4d0 [bugpoint] Delete -safe-llc and make -run-llc work like -run-llc -safe-run-llc
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   f6fa4d0..ea1f497  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to ea1f49741ec4c0a37796b88f6bb8d09d7ab1e8c3.
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!