Since commit v3.8.0-rc1~232^2 (execute_process: Add ENCODING option for
Windows child process output, 2016-11-23) we decode child process output
using the console's active codepage by default.  This differs from
previous versions of CMake and is therefore incompatible.  Changing this
default will require a policy, so for now revert the default behavior
back to performing no decoding.

Reported-by: Nils Gladitz <nilsgladitz@gmail.com>