tcg: Add helper_unaligned_{ld,st} for user-only sigbus

To be called from tcg generated code on hosts that support
unaligned accesses natively, in response to an access that
is supposed to be aligned.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2 files changed