rust: define custom link arguments on aarch64-apple-darwin

We need these to avoid undefined symbols during linking.

Author: indygreg

.cargo/config.toml

@@ -1,2 +1,5 @@
+[target.aarch64-apple-darwin]
+rustflags = ["-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup"]
+
 [target.x86_64-apple-darwin]
 rustflags = ["-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup"]