Will manually controlling both an accelerometer and a gyroscope at the
same time be reasonable to do? No idea. Was this easy to implement
thanks to the input override system? Yes.
Fixes https://bugs.dolphin-emu.org/issues/12443.
This gets rid of a blocking operation, improving performance and fixing
https://bugs.dolphin-emu.org/issues/12893.
This also makes us no longer directly access the state of certain UI
elements from the CPU thread, which probably wasn't thread-safe but
doesn't seem to have caused any observable issues so far.
This resulted in the labels being solid black even when audio stretching is disabled the first time the settings are opened, but then properly being greyed out after changing a setting (even the audio backend or DSP emulation engine, not just whether audio stretching is enabled).
Before these changes you could tell Dolphin to convert a game file into the same format it is already in, leading to the FileDialog using the input path as the default destination path
An unsuspecting user could then click Save and Dolphin would try to convert the input file by writing the destination file on top of it... leading to an I/O error and the input file being entirely removed
This avoids a pseudo infinite loop where CodeWidget::UpdateCallstack
would lock the CPU in order to read the call stack, causing the CPU to
call Host_UpdateDisasmDialog because it's transitioning from running to
pausing, causing Host::UpdateDisasmDialog to be emitted, causing
CodeWidget::Update to be called, once again causing
CodeWidget::UpdateCallstack to be called, repeating the cycle.
Dolphin didn't go completely unresponsive during this, because
Host_UpdateDisasmDialog schedules the emitting of Host::UpdateDisasmDialog
to happen on another thread without blocking, but it was stopping certain
operations like exiting emulation from working.
This fixes a problem I was having where using frame advance with the
debugger open would frequently cause panic alerts about invalid addresses
due to the CPU thread changing MSR.DR while the host thread was trying
to access memory.
To aid in tracking down all the places where we weren't properly locking
the CPU, I've created a new type (in Core.h) that you have to pass as a
reference or pointer to functions that require running as the CPU thread.
