Feature: Support `filename:function` syntax for pdb break and clear command

Feature or enhancement

Proposal:

Currently, pdb's break command supports filename:lineno or just function (in the current context or imported modules). However, it does not support the filename:function syntax.

Attempting to use break filename:function usually results in a Error because pdb expects the part after the colon to be a line number.

main.py:

def foo():
    pass

bash-5.3# ./python -m pdb main.py
> /workspaces/cpython/main.py(1)<module>()
-> def foo():
(Pdb) b main:foo
*** Bad lineno: foo

This syntax is useful for specifying a function in a specific file, especially to disambiguate if multiple files have the same function name, or if the file hasn't been loaded yet but the user wants to be explicit.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-142470

Comienza con el manejo existente de los comandos break y clear de pdb, comparando las rutas de resolución de filename:lineno y function. Reproduce el ejemplo de main.py con b main:foo y, a continuación, verifica que filename:function funcione sin hacer regresiones en las formas existentes; el issue hace referencia al PR vinculado gh-142470.