target/m68k: Raise the TRAPn exception with the correct pc

Rather than adjust the PC in all of the consumers, raise
the exception with the correct PC in the first place.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220602013401.303699-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/m68k/cpu_loop.c

@@ -56,7 +56,6 @@ void cpu_loop(CPUM68KState *env)
             {
                 abi_long ret;
                 n = env->dregs[0];
-                env->pc += 2;
                 ret = do_syscall(env,
                                  n,
                                  env->dregs[1],

target/m68k/op_helper.c

@@ -217,11 +217,6 @@ static void cf_interrupt_all(CPUM68KState *env, int is_hw)
             cpu_loop_exit(cs);
             return;
         }
-        if (cs->exception_index >= EXCP_TRAP0
-            && cs->exception_index <= EXCP_TRAP15) {
-            /* Move the PC after the trap instruction.  */
-            retaddr += 2;
-        }
     }
 
     vector = cs->exception_index << 2;
@@ -304,10 +299,6 @@ static void m68k_interrupt_all(CPUM68KState *env, int is_hw)
             /* Return from an exception.  */
             m68k_rte(env);
             return;
-        case EXCP_TRAP0 ...  EXCP_TRAP15:
-            /* Move the PC after the trap instruction.  */
-            retaddr += 2;
-            break;
         }
     }
 

target/m68k/translate.c

@@ -4860,7 +4860,7 @@ DISAS_INSN(wdebug)
 
 DISAS_INSN(trap)
 {
-    gen_exception(s, s->base.pc_next, EXCP_TRAP0 + (insn & 0xf));
+    gen_exception(s, s->pc, EXCP_TRAP0 + (insn & 0xf));
 }
 
 static void gen_load_fcr(DisasContext *s, TCGv res, int reg)