Adding 'int.__bool__' method

Author: mrveera

tests/snippets/numbers.py

@@ -8,3 +8,7 @@ class A(int):
 x = A(7)
 assert x == 7
 assert type(x) is A
+
+assert int(2).__bool__() == True
+assert int(0.5).__bool__() == False
+assert int(-1).__bool__() == True

vm/src/obj/objint.rs

@@ -90,6 +90,11 @@ impl FromPyObjectRef for BigInt {
     }
 }
 
+fn int_bool(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(zelf, Some(vm.ctx.int_type()))]);
+    let result = !BigInt::from_pyobj(zelf).is_zero();
+    Ok(vm.ctx.new_bool(result))
+}
 fn int_eq(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
@@ -527,6 +532,7 @@ pub fn init(context: &PyContext) {
     context.set_attr(&int_type, "__format__", context.new_rustfunc(int_format));
     context.set_attr(&int_type, "__truediv__", context.new_rustfunc(int_truediv));
     context.set_attr(&int_type, "__xor__", context.new_rustfunc(int_xor));
+    context.set_attr(&int_type, "__bool__", context.new_rustfunc(int_bool));
     context.set_attr(
         &int_type,
         "bit_length",