[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at abd70fb [lld-macho] Export trie addresses should be relative to the image base
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   abd70fb..dbc616e  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to dbc616e9825080f617865f7698647985d7c24e5e.
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!