target/microblaze: Use tcg_gen_lookup_and_goto_ptr

Normal indirect jumps, or page-crossing direct jumps, can use
tcg_gen_lookup_and_goto_ptr to avoid returning to the main loop
simply to find an existing TB for the next pc.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/microblaze/translate.c

@@ -147,7 +147,7 @@ static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
         tcg_gen_exit_tb(dc->base.tb, n);
     } else {
         tcg_gen_movi_i32(cpu_pc, dest);
-        tcg_gen_exit_tb(NULL, 0);
+        tcg_gen_lookup_and_goto_ptr();
     }
     dc->base.is_jmp = DISAS_NORETURN;
 }
@@ -1803,7 +1803,7 @@ static void mb_tr_tb_stop(DisasContextBase *dcb, CPUState *cs)
         if (unlikely(cs->singlestep_enabled)) {
             gen_raise_exception(dc, EXCP_DEBUG);
         } else {
-            tcg_gen_exit_tb(NULL, 0);
+            tcg_gen_lookup_and_goto_ptr();
         }
         return;