linux-user/alpha: Set FPE_FLTUNK for gentrap ROPRAND

This si_code was changed in 4cc13e4f6d441, for linux 4.17.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220107213243.212806-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/alpha/cpu_loop.c

@@ -151,7 +151,7 @@ void cpu_loop(CPUAlphaState *env)
                     info.si_code = TARGET_FPE_FLTRES;
                     break;
                 case TARGET_GEN_ROPRAND:
-                    info.si_code = 0;
+                    info.si_code = TARGET_FPE_FLTUNK;
                     break;
                 default:
                     info.si_signo = TARGET_SIGTRAP;