[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 6fe6b29 AMDGPU: Fix assertion in performSHLPtrCombine for 64-bit pointers
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   6fe6b29..7f5928e  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 7f5928ef5a5743ee7e65c6c9d1e1c9bc6af03063.
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!