[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at c530539 [AArch64][NFC] require aarch64 support for hwasan test
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   c530539..55de46f  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 55de46f3b2c5651b06e4739209907f14ab781d89.
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!