This reworks how host<->device synchronization works on the Vulkan
backend. Instead of "protecting" resources with a fence and signalling
these as free when the fence is known to be signalled by the host GPU,
use timeline semaphores.

Vulkan timeline semaphores allow use to work on a subset of D3D12
fences. As far as we are concerned, timeline semaphores are a value set
by the host or the device that can be waited by either of them.

Taking advantange of this, we can have a monolithically increasing
atomic value for each submission to the graphics queue. Instead of
protecting resources with a fence, we simply store the current logical
tick (the atomic value stored in CPU memory). When we want to know if a
resource is free, it can be compared to the current GPU tick.

This greatly simplifies resource management code and the free status of
resources should have less false negatives.

To workaround bugs in validation layers, when these are attached there's
a thread waiting for timeline semaphores.

video_core: Enforce -Werror=switch

bis_factory/romfs_factory: Eliminate dependencies on the global system instance

core/loader: Remove dependencies on the global system instance

This forces us to fix all -Wswitch warnings in video_core.

Now all that remains is:

18 instances in file_sys code
14 instances in GDB stub code (this can be tossed wholesale)
4 instances in HLE code
2 instances in settings code.

 nca_patch: Reduce stack usage size within SearchBucketEntry()

cheat_engine: Remove unnecessary system argument to CheatParser's Parse function

Previously this function was using ~16KB of stack (16528 bytes), which
was caused by the function arguments being taken by value rather than by
reference.

We can make this significantly lighter on the stack by taking them by
reference.

This is only used internally and doesn't depend on any class state, so
we can make it fully internal.

We don't need to create two separate instantiations of the same code, we
can simply make the character template argument a regular function
parameter.

This isn't used within the function at all in any implementations, so we
can remove it entirely.

patch_manager: Minor cleanup

We make it explicit that we're truncating arithmetic here to resolve
compiler warnings (even if the sizes weren't u32/u64 arithmetic
generally promotes to int :<)

We can use these to avoid typing the same type redundantly. This way, if
these ever change, only a single location needs to be modified.

These functions are only used within this translation unit, so we can
make them internally linked.

crypto/key_manager: Remove dependency on the global system accessor

We can supply the content provider as an argument instead of hardcoding
a global accessor in the implementation.

kernel: Remove all dependencies on the global system instance

With this, the kernel finally doesn't depend directly on the global
system instance anymore.

service: Remove two usages of the global system accessor

kernel/scheduler: Use std::mutex instead of spin lock

Remove bad and useless packages from LGTM build

cmake: Update to Qt 5.12.8

bsd: Resolve a few warnings

audio_core: Apollo Part 1, AudioRenderer refactor

It still fails due to CMake version being 3.13.4, but at
least we are not ones to blame now.

Project Mjölnir: Part 2 - Controller Applet

configure_input_player: Resolve sign conversion warnings in UpdateMappingWithDefaults()

video_core: Remove all Core::System references in renderer

gc_adapter: Make DeviceConnected() a const member function

Removes more instances of reliance on global state.

This doesn't modify instance state, so it can be made const.

Previously the address provided to SendToImpl would never be propagated
to SendTo(). This fixes that.

Same behavior, less typing.