[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 53e92b4 [InstCombine] (~A & B) ^ A -> A | B
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   53e92b4..ec54867df master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to ec54867df5e7f20e12146e628af34f0384308bcb.
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!