Proposal: Consistent handling of call for not parameters for type creating built-in functions

[lgalfaso]

The built-in functions that convert one type to another (whenever this is possible) are split into two buckets:

• The ones that can handle being called with no parameters (bool, float, list, tuple, dict, set)
• The ones that fail whenever called with no parameters (str, int, bytes)

In order to be consistent, I propose to allow all of these functions to be called without any parameters. This would imply that str() == "", int() == 0 and bytes() == b'' (today, all of these calls should fail).

This is behaviour would be consistent with Python.