Ninja runs just one command line for every build statement, so the Ninja
generator needs to `&&`-chain multiple commands together into one long
string. For long custom command sequences this can exceed the maximum
command-line length for the operating system. In such cases, write the
commands out to a script instead, and then run the script from Ninja's
one command line.
Co-Author: Brad King <brad.king@kitware.com>
Fixes: #15612
