tcg/optimize: Simplify fold_eqv constant checks

Both cases are handled by fold_xor after conversion.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/optimize.c

@@ -1948,9 +1948,7 @@ static bool fold_eqv(OptContext *ctx, TCGOp *op)
     uint64_t z_mask, o_mask, s_mask;
     TempOptInfo *t1, *t2;
 
-    if (fold_const2_commutative(ctx, op) ||
-        fold_xi_to_x(ctx, op, -1) ||
-        fold_xi_to_not(ctx, op, 0)) {
+    if (fold_const2_commutative(ctx, op)) {
         return true;
     }