target/sh4: Hoist register bank selection

Compute which register bank to use once at the start of translation.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-11-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
1 file changed