target/xtensa: don't continue translation after exception

There's no point in continuing translating guest instructions once an
unconditional exception is thrown.
There's also no point in updating pc before any instruction is
translated, don't do it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

target/xtensa/translate.c

@@ -3152,8 +3152,11 @@ void gen_intermediate_code(CPUXtensaState *env, TranslationBlock *tb)
         goto done;
     }
     if (tb->flags & XTENSA_TBFLAG_EXCEPTION) {
-        tcg_gen_movi_i32(cpu_pc, dc.pc);
+        tcg_gen_insn_start(dc.pc);
+        ++insn_count;
         gen_exception(&dc, EXCP_DEBUG);
+        dc.is_jmp = DISAS_UPDATE;
+        goto done;
     }
 
     do {