validation-test/stlib/Glibc.swift was failing on powerpc64le due to the
missing TIOCGWINSZ symbol. Since (from what I can tell) this is just a
random tty ioctl, replace it with a different ioctl that should be more
commonly defined.
Signed-off-by: Russell Currey <ruscur@russell.cc>
This is needed if we compile StdlibUnittest with -sil-serialize-all
So far I added the imports only in files which needed them. But this may change, depending on the optimizer (inlining).
Adding them in all files doesn't harm and avoids confusion if someone makes an unrelated change which would result in such a linker error.
