Resolve warning caused by using values from two different enums in a
conditional expression which was deprecated in c++20.
The warning in question is clang -Wdeprecated-anon-enum-enum-conversion
and gcc -Wenum-compare.
We had one implementation of this type of data structure in Arm64Emitter
and one in VideoCommon. This moves the Arm64Emitter implementation to
its own file and adds begin and end functions to it, so that VideoCommon
can use it.
You may notice that the license header for the new file is CC0. I wrote
the Arm64Emitter implementation of SmallVector, so this should be no
problem.
This fixes a problem that started happening in CoreTimingTest after the
previous commit. CPUThreadConfigCallback registers a Config callback
only once per run of the process, but CoreTimingTest calls
Config::Shutdown after each test, and Config::Shutdown was clearing all
callbacks, preventing the callback from running after that.
In theory, our config system supports calling Set from any thread. But
because we have config callbacks that call RunAsCPUThread, it's a lot
more restricted in practice. Calling Set from any thread other than the
host thread or the CPU thread is formally thread unsafe, and calling Set
on the host thread while the CPU thread is showing a panic alert causes
a deadlock. This is especially a problem because 04072f0 made the
"Ignore for this session" button in panic alerts call Set.
Because so many of our config callbacks want their code to run on the
CPU thread, I thought it would make sense to have a centralized way to
move execution to the CPU thread for config callbacks. To solve the
deadlock problem, this new way is non-blocking. This means that threads
other than the CPU thread might continue executing before the CPU thread
is informed of the new config, but I don't think there's any problem
with that.
Intends to fix https://bugs.dolphin-emu.org/issues/13108.
Android interprets char as unsigned char, so comparing with 0 triggers a
tautological-unsigned-char-zero-compare warning.
Casting c to an unsigned char and removing the comparison with 0
resolves the warning while needing one less comparison on all platforms.
