Share debuginfo testsuite breakpoint setup logic

[jieyouxu]

To follow up: I think the way we are setting breakpoints in our tests is pretty consistent and would probably be compatible with the approach of setting the breakpoint by function name and then looking one frame up. It would be good if that function was defined in a central place (so we don't have to copy-and-paste it into every test file) and then we'd have to update the test runner and documentation.

Originally posted by @michaelwoerister in #71437