[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ee7caa7 Reland [llvm-exegesis] Add benchmark latency option on X86 that uses LBR for more precise measurements.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ee7caa7..902cbcd  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 902cbcd59e22ccd853f6b0c22acc772fd955dc46.
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!