tcg/aarch64: Apple does not align __int128_t in even registers

tcg/aarch64: Apple does not align __int128_t in even registers

From https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms

  When passing an argument with 16-byte alignment in integer registers,
  Apple platforms allow the argument to start in an odd-numbered xN
  register. The standard ABI requires it to begin in an even-numbered
  xN register.

Cc: qemu-stable@nongnu.org
Fixes: 5427a9a7604 ("tcg: Add TCG_TARGET_CALL_{RET,ARG}_I128")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2169
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <9fc0c2c7-dd57-459e-aecb-528edb74b4a7@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>