powerpc workaround

Author: gnzlbg

crates/coresimd/tests/reductions.rs

@@ -5,6 +5,10 @@ extern crate stdsimd;
 
 use stdsimd::simd::*;
 
+macro_rules! is_powerpc_feature_detected {
+    ($t:tt) => { true }
+}
+
 macro_rules! invoke_arch {
     ($macro:ident, $feature_macro:ident, $id:ident, $elem_ty:ident,
      [$($feature:tt),*]) => {