[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d35e2c1 AMDGPU/GlobalISel: Fix not constraining ds_append/consume operands
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d35e2c1..17eafe0  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 17eafe0841d6e523d410771c8d4de99d5881c59d.
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!