[Bug libstdc++/96817] __cxa_guard_acquire unsafe against dynamically loaded pthread

[yshuiv7 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96817

--- Comment #1 from Yuxuan Shui <yshuiv7 at gmail dot com> ---
Example:

This program normally deadlocks when using linked pthread:

https://godbolt.org/z/Yrza4e

But it will throw recursive_init_error when using dlopen'd pthread:

https://godbolt.org/z/afMe5d