gh-123165: correct tests for dis.dis(func, show_positions=True)

[picnixz]

Mark suggested simplifying the faking of positions information via ast manipulation so here it is.

cc @iritkatriel @markshannon

• Issue: Add show_positions keyword argument to dis.dis and related functions #123165

[iritkatriel]

Note: if someone knows a way to include partial positions information as well as no position information (but only for a single instruction, and not for the entire code object otherwise we cannot test the -- rendering) by changing AST nodes only, please tell me.

The same way that dis tests '--' for line numbers should work. It inputs python code that gets compiled into something that needs '--'.

[picnixz]

It inputs python code that gets compiled into something that needs '--'.

Mmh, yes it was dumb of me. I'll try this approach now.

[picnixz]

The tests are a bit longer (in length) but at least I don't need some magical construction that I would forget about tomorrow :D Thank you all for the tips.

[iritkatriel]

LGTM