tcg-i386: Tidy move operations. Define OPC_MOVB* and OPC_MOVL*; use them throughout. Use tcg_out_ld/st instead of bare tcg_out_modrm_offset when it makes sense. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>