gh-125884: Support breakpoint on functions with annotations

[gaogaotiantian]

close #125885 as well.

Two things are fixed:

1. The regex for a function definition is improved to include generics
2. We do not rely on the function code object being the first const in the compiled code object. We search for it.

• Issue: pdb fails when setting a breakpoint to function names with return-type annotations #125884

[iritkatriel]

I think this is easier to read:

Suggested change

	for const in code.co_consts:
	if isinstance(const, CodeType) and const.co_name == funcname:
	funccode = const
	break
	else:
	continue
	try:
	next(c for c in code.co_consts if isinstance(c, CodeType) and c.co_name == funcname)
	except StopIteration:
	continue

[gaogaotiantian]

I don't that's equivalent. The assignment to funccode is missing. Personally I think the original is easier to read. The modified one is definitely shorter, but the usage of next and StopIteration is pretty tricky.

[gaogaotiantian]

Hmm, I don't think the continue part is correct, that should not happen. I'll try to fix it.

[iritkatriel]

Are there tests for functions with decorators?

[gaogaotiantian]

Not really. What's the expected behavior? We can't resolve the decorator in pdb, we will only add the breakpoint inside the decorated function.

[gaogaotiantian]

Well, that's not true.. It depends on whether the function is in the name space. If it's already in the namespace, we will set the breakpoint in the decorator.