tcg/optimize: fix setcond2 optimization

When setcond2 is rewritten into setcond, the state of the destination
temp should be reset, so that a copy of the previous value is not
used instead of the result.

Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

tcg/optimize.c

@@ -1057,6 +1057,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 /* Simplify LT/GE comparisons vs zero to a single compare
                    vs the high word of the input.  */
                 s->gen_opc_buf[op_index] = INDEX_op_setcond_i32;
+                reset_temp(args[0]);
                 gen_args[0] = args[0];
                 gen_args[1] = args[2];
                 gen_args[2] = args[4];