Data race between ThreadPool.Performance.read and ...Performance.add

[IntegratedQuantum]

Trace:

  Read of size 8 at 0x7ffff7e2b088 by main thread:
    #0 __tsan_memcpy ??:? (Cubyzig+0xda8dfb)
    #1 utils.ThreadPool.Performance.read /home/mint/Cubyz/src/utils.zig:1118 (Cubyzig+0x54703f)
    #2 windows.debug.render /home/mint/Cubyz/src/gui/windows/debug.zig:71 (Cubyzig+0x4a6072)
    #3 GuiWindow.render /home/mint/Cubyz/src/gui/GuiWindow.zig:488 (Cubyzig+0x4c2e84)
    #4 gui.updateAndRenderGui /home/mint/Cubyz/src/gui/gui.zig:548 (Cubyzig+0x475968)
    #5 main.main /home/mint/Cubyz/src/main.zig:669 (Cubyzig+0x46473c)
    #6 start.callMain /home/mint/Cubyz/compiler/zig/lib/std/start.zig:608 (Cubyzig+0x46321b)
    #7 start.callMainWithArgs /home/mint/Cubyz/compiler/zig/lib/std/start.zig:577 (Cubyzig+0x46321b)
    #8 start.main /home/mint/Cubyz/compiler/zig/lib/std/start.zig:592 (Cubyzig+0x46321b)
    #9 __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58 (libc.so.6+0x29d8f) (BuildId: 490fef8403240c91833978d494d39e537409b92e)

  Previous atomic write of size 4 at 0x7ffff7e2b08c by thread T5:
    #0 atomic.Value(u32).swap /home/mint/Cubyz/compiler/zig/lib/std/atomic.zig:48 (Cubyzig+0x5a2d50)
    #1 Thread.Mutex.FutexImpl.lockSlow /home/mint/Cubyz/compiler/zig/lib/std/Thread/Mutex.zig:189 (Cubyzig+0x5a2d50)
    #2 Thread.Mutex.FutexImpl.lock /home/mint/Cubyz/compiler/zig/lib/std/Thread/Mutex.zig:154 (Cubyzig+0x4ed91c)
    #3 Thread.Mutex.DebugImpl.lock /home/mint/Cubyz/compiler/zig/lib/std/Thread/Mutex.zig:74 (Cubyzig+0x479452)
    #4 Thread.Mutex.lock /home/mint/Cubyz/compiler/zig/lib/std/Thread/Mutex.zig:34 (Cubyzig+0x479452)
    #5 utils.ThreadPool.Performance.add /home/mint/Cubyz/src/utils.zig:1099 (Cubyzig+0x71a595)
    #6 utils.ThreadPool.run /home/mint/Cubyz/src/utils.zig:1205 (Cubyzig+0x6789bc)
    #7 Thread.callFn__anon_31500 /home/mint/Cubyz/compiler/zig/lib/std/Thread.zig:409 (Cubyzig+0x5b539d)
    #8 Thread.PosixThreadImpl.spawn__anon_15663.Instance.entryFn /home/mint/Cubyz/compiler/zig/lib/std/Thread.zig:678 (Cubyzig+0x50379f)

Not a big deal since this value is never read after copying, but it still clogs up the thread sanitizer output.