jq dumps JSON to the Windows console as UTF-16 with WriteConsoleW(),
but priv_fwrite() still writes the raw UTF-8 bytes with WriteFile(),
which the console decodes with its output code page. So `jq .k` prints
non-ASCII correctly while `jq -r .k` prints mojibake, and the same goes
for -j, --raw-output0, --seq, halt_error and the `stderr` builtin.
The tty flag is computed once, from stdout, and passed to writes aimed
at stderr too, so ask the handle instead: with stdout on a console and
stderr redirected, WriteConsoleW() failed on the file handle and the
output was dropped.
One byte-level change: with stdout on a console and stderr redirected,
halt_error and the `stderr` builtin now go through the CRT, so bare LF
becomes CRLF and an existing CRLF becomes CR CRLF. Use -b for
byte-exact output on that stream.
