Add weakproxy bool

Lib/test/test_weakref.py

@@ -162,8 +162,6 @@ class ReferencesTestCase(TestBase):
         c = C()
         self.assertRaises(TypeError, weakref.ref, c, callback=None)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_proxy_ref(self):
         o = C()
         o.bar = 1
@@ -405,8 +403,6 @@ class ReferencesTestCase(TestBase):
         del f[0]
         self.assertEqual(f.result, 0)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_proxy_bool(self):
         # Test clearing of SF bug #1170766
         class List(list): pass

vm/src/builtins/weakproxy.rs

@@ -73,6 +73,11 @@ impl PyWeakProxy {
         self.try_upgrade(vm)?.length(vm)
     }
 
+    #[pymethod(magic)]
+    fn bool(&self, vm: &VirtualMachine) -> PyResult<bool> {
+        self.try_upgrade(vm)?.is_true(vm)
+    }
+
     fn contains(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<bool> {
         let obj = self.try_upgrade(vm)?;
         PySequence::contains(&obj, &needle, vm)