[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 511d5aa [Transforms][SROA] Skip uses of allocas where the type is scalable
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   511d5aa..a0c2c6a  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to a0c2c6aa420e572520337b782410c0c04ba87b69.
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!