[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 6f9d84b Revert "hwasan: Disable operator {new,delete} interceptors when interceptors are disabled."
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   6f9d84b..d5adadb  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d5adadb3a564236a894cbb5f189496a65d9e9742.
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!