CMake Nightly Date Stamp
Fix CMAKE_HOST_SYSTEM_PROCESSOR detection on GNU/Hurd (#15147)

On Debian GNU/Hurd 'uname -p' prints "unknown", so use 'uname -m'
instead.
Merge topic 'fix-gnu-hurd-host-detection' into next

89d7a5a4 Fix CMAKE_HOST_SYSTEM_PROCESSOR detection on GNU/Hurd (#15147)
e03b474f CMake Nightly Date Stamp