[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 55c0f12 [compiler-rt][sanitizers] Fix Solaris madvise declaration
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   55c0f12..59a76d9  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 59a76d957a2603ee0548293ded170c98e1308c48.
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!