disable some testing on powerpc

Author: AaronKutch

testcrate/tests/conv.rs

@@ -38,7 +38,12 @@ macro_rules! i_to_f {
                 }
                 // Test against native conversion. We disable testing on all `x86` because of
                 // rounding bugs with `i686`.
-                if !cfg!(target_arch = "x86") && f0 != f1 {
+                if !(f0 == f1
+                    || cfg!(target_arch = "x86")
+                    || cfg!(target_arch = "powerpc")
+                    || cfg!(target_arch = "powerpc64")
+                    || cfg!(target_arch = "powerpc64le")
+                ) {
                     panic!(
                         "{}({}): std: {}, builtins: {}",
                         stringify!($fn),