[Issue 20270] [REG2.087] Deadlock in garbage collection when running processes in parallel

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20270

--- Comment #7 from Rainer Schuetze <r.sagitario at gmx.de> ---
I have reproduced the issue when running the test for a higher number of times.
Not sure why this doesn't appear more often. Please try
https://github.com/dlang/druntime/pull/2816

--