astroid 2.0.0 chokes on recursion

[hroncok]

Steps to reproduce

https://github.com/PyCQA/astroid/blob/master/astroid/tests/testdata/python3/data/joined_strings.py

import astroid
import pathlib
astroid.MANAGER.optimize_ast = True
source = pathlib.Path('joined_strings.py').read_text()
builder = astroid.builder.AstroidBuilder()
tree = builder.string_build(source)

Current behavior with 1.6

No exception.

Current behavior with 2.0

RecursionError: maximum recursion depth exceeded

This breaks asttokens tests: gristlabs/asttokens#16

[PCManticore]

I think this is fine. In the past we used to have a hack for supporting joining thousands of strings together, but we decided to remove that hack with this release. There's no need to support such an use case as it's not going to happen in real life, and if it does, then there's no expectation for astroid to work on that IMO. What asttokens might be doing is running astroid over the data test files from astroid, as I can see from their repo, but I suggest that they should remove the joined_strings file as it's no longer a supported use case. Here's the removal of that hack for reference 5176976.