this was noticed in pyflakes's testsuite: https://github.com/PyCQA/pyflakes/pull/532#pullrequestreview-396059622

I've created a small script to reproduce the problem

```
import sys

SRC = b"""\
def foo():
    '''

def bar():
    pass

def baz():
    '''quux'''
"""

try:
    exec(SRC)
except SyntaxError as e:
    print(
        f'{sys.version}\n\n'
        f'{type(e).__name__}:\n'
        f'- line: {e.lineno}\n'
        f'- offset: {e.offset}\n'
        f'- text: {e.text!r}\n'
    )
```

This was "fixed" in python3.8, but has regressed:

```
$ python3.6 t2.py
3.6.9 (default, Nov  7 2019, 10:44:02) 
[GCC 8.3.0]

SyntaxError:
- line: 8
- offset: 52
- text: "    '''\n\ndef bar():\n    pass\n\ndef baz():\n    '''quux'''\n"

$ python3.8 t2.py
3.8.2 (default, Feb 26 2020, 02:56:10) 
[GCC 7.4.0]

SyntaxError:
- line: 8
- offset: 8
- text: "    '''\n\ndef bar():\n    pass\n\ndef baz():\n    '''quux'''\n"

$ ./python t2.py
3.9.0a5+ (heads/master:3955da8568, Apr 19 2020, 14:29:48) 
[GCC 7.5.0]

SyntaxError:
- line: 8
- offset: 52
- text: "    '''\n\ndef bar():\n    pass\n\ndef baz():\n    '''quux'''\n"

```