tsan: add another fork deadlock test

The test tries to provoke internal allocator to be locked during fork
and then force the child process to use the internal allocator.
This test sometimes deadlocks with the new tsan runtime.

Depends on D114514.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D114515

GitOrigin-RevId: a68b52e0a33382f241a250c1d67bed1141727447
1 file changed