[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at fc7d290 [OpenMP] Use common interface to access GPU Grid Values
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   fc7d290..30371df  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 30371df85f3e6fc2352647566f92c9079f77b2c7.
CMake Error at CMakeLists.txt:6 (message):
  Your CMake version is 3.7.1.  The minimum version of CMake required to
  build LLVM is now 3.13.4.


-- Configuring incomplete, errors occurred!