target/arm: Diagnose UNALLOCATED in disas_simd_two_reg_misc_fp16

target/arm: Diagnose UNALLOCATED in disas_simd_two_reg_misc_fp16

This fprintf+assert has been in place since the beginning.
It is prior to the fp_access_check, so we're still good to
raise sigill here.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/381
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210604183506.916654-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>