TestDeletionRace for SWBP deletion race condition

[3rdit]

Test for x64dbg/GleeBug#76 and x64dbg/TitanEngine#29

1. Write 0xCC to RaceFunction and store in the breakpoint map
2. 5 threads call RaceFunction 1,000 times each
3. On hit #10, remove the breakpoint from map and restore original byte
4. If, say, Thread B, had already executed 0xCC before deletion but the event wasnt processed yet, it would fail.

Will require running a few times as it is a race, but with the PR changes it should never fail. I notice it's about a ~40% fail rate on current, but with the fix I haven't failed once.