util/iov: Fix -O1 uninitialized variable warning

At -O2, code in the form

  if (p) A; B; if (p) C;

may be rearranged via "jump threading" into

  if (p) { A; B; C; } else { B; }

But at -O1 this doesn't happen and we -Werror out here on
the "may be used uninitialized" orig_len.  Perform this transform
by hand so that -O1 remains a viable debugging alternative.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Merge branches 'auxv', 'axp-next', 'disas', 'fix-iov', 'tcg-next' and 'tcg-ool-ppc' into working
tcg-alpha: Fix type mismatch errors in cpu_signal_handler.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-alpha: New TCG target.

This began with a patch from Dong Weiyu <cidentifier@yahoo.com.cn>,
and was modified to fix problems and to adapt to changes in TCG.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-alpha: Implement tcg_register_jit

Signed-off-by: Richard Henderson <rth@twiddle.net>