Merge branch 'fix-refcast' into 'develop'

fix

See merge request !36

src/ast/src/types.rs

@@ -158,7 +158,7 @@ impl MuType {
 
     pub fn is_funcref(&self) -> bool {
         match self.v {
-            MuType_::Struct(_) => true,
+            MuType_::FuncRef(_) => true,
             _ => false
         }
     }

src/vm/api/api_impl/muirbuilder.rs

@@ -2725,10 +2725,9 @@ impl<'lb, 'lvm> BundleLoader<'lb, 'lvm> {
                                      impl_to_ty.is_double())
                         }
                         ConvOp::REFCAST => {
-                            (impl_from_ty.is_ref() || impl_from_ty.is_iref() ||
-                                 impl_from_ty.is_funcref()) &&
-                                (impl_to_ty.is_ref() || impl_to_ty.is_iref() ||
-                                     impl_to_ty.is_funcref())
+                            (impl_from_ty.is_ref() && impl_to_ty.is_ref()) ||
+                            (impl_from_ty.is_iref() && impl_to_ty.is_iref()) ||
+                            (impl_from_ty.is_funcref() && impl_to_ty.is_funcref())
                         }
                         ConvOp::PTRCAST => {
                             (impl_from_ty.is_ptr() || impl_from_ty.is_int()) &&