Change int.conjugate() to return a new int

This results in the correct behavior (that is, matching CPython) for
both int and bool types.

Also adding a bool conjugate test.

Author: agude

tests/snippets/bools.py

@@ -46,4 +46,5 @@ def __bool__(self):
 assert False * 7 == 0
 assert True > 0
 assert int(True) == 1
-#assert True.conjugate() == 1
+assert True.conjugate() == 1
+assert isinstance(True.conjugate(), int)

vm/src/obj/objint.rs

@@ -491,7 +491,8 @@ fn int_bit_length(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 fn int_conjugate(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(i, Some(vm.ctx.int_type()))]);
-    Ok(i.clone())
+    let v = get_value(i);
+    Ok(vm.ctx.new_int(v))
 }
 
 pub fn init(context: &PyContext) {