[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 1298252 [X86] Move 'int $3' -> 'int3' handling in the assembler to processInstruction.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   1298252..1d78e21  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 1d78e2101ab75f01615a45467c44da7181cccedb.
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!