[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 398b810 [ELF] Don't crash on R_X86_64_GOTPCRELX for test/binop instructions
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   398b810..aaa8b44  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to aaa8b44d19918ea1764339224cec68c27445aa8e.
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!