[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 1ef3ed0 GlobalISel: Rewrite getLCMType
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   1ef3ed0..38fbba4  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 38fbba4cb830e48476781f9135a92450c1f5510d.
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!