Add weakproxy bytes

Lib/test/test_weakref.py

@@ -258,8 +258,6 @@ class ReferencesTestCase(TestBase):
         self.assertEqual(L3[:5], p3[:5])
         self.assertEqual(L3[2:5], p3[2:5])
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_proxy_unicode(self):
         # See bug 5037
         class C(object):

vm/src/builtins/weakproxy.rs

@@ -78,6 +78,11 @@ impl PyWeakProxy {
         self.try_upgrade(vm)?.is_true(vm)
     }
 
+    #[pymethod(magic)]
+    fn bytes(&self, vm: &VirtualMachine) -> PyResult {
+        self.try_upgrade(vm)?.bytes(vm)
+    }
+
     fn contains(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<bool> {
         let obj = self.try_upgrade(vm)?;
         PySequence::contains(&obj, &needle, vm)