This came up in the code review for PHPLIB-1001.

Both DocumentMatchConstraint (legacy test runner) and IsBsonType (unified test runner) only allow Int64 objects for "long" on a 32-bit platform (i.e. PHP_INT_SIZE is 4). There is no need to be this strict, and it could actually lead to an assertion failure since PHPC only instantiates Int64 when necessary. A 64-bit BSON integer with a value in the range of a signed 32-bit integer would decode as an integer primitive.

We can easily change this to just allow "long" to match both Int64 or an integer on any platform.