Merge branch 'js/test-lib-windows-emulated-yes'

The emulated "yes" command used in our test scripts has been tweaked not to spend too much time generating unnecessary output that is not used, to help those who test on Windows where it would not stop until it fills the pipe buffer due to lack of SIGPIPE. * js/test-lib-windows-emulated-yes: test-lib: limit the output of the yes utility