fix iOS

flutter_filament/ios/Classes/ResourceBuffer.c

@@ -0,0 +1,10 @@
+#include "ResourceBuffer.h"
+
+ResourceLoaderWrapper *make_resource_loader(LoadFilamentResourceFromOwner loadFn, FreeFilamentResourceFromOwner freeFn, void *const owner)
+{
+    ResourceLoaderWrapper *rlw = (ResourceLoaderWrapper *)malloc(sizeof(ResourceLoaderWrapper));
+    rlw->loadFromOwner = loadFn;
+    rlw->freeFromOwner = freeFn;
+    rlw->owner = owner;
+    return rlw;
+}