[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 6d8eea6 [AArch64][LV] Move vectorizer test to Transforms/LoopVectorize/AArch64. NFC
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   6d8eea6..96bd4d3  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 96bd4d34a220359662d21b0a60e74e15c3d19663.
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!