tcg: Rename debug_insn_start to insn_start

With an eye toward making it mandatory.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

target-unicore32/translate.c

@@ -1795,7 +1795,7 @@ static void disas_uc32_insn(CPUUniCore32State *env, DisasContext *s)
     unsigned int insn;
 
     if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP | CPU_LOG_TB_OP_OPT))) {
-        tcg_gen_debug_insn_start(s->pc);
+        tcg_gen_insn_start(s->pc);
     }
 
     insn = cpu_ldl_code(env, s->pc);