Versions prior to this didn't compile on OpenBSD due to unconditional
use of the non-standard strtod_l() function.
The fmt::MemoryWriter API has been removed in the intervening
versions, so replace its use with fmt::memory_buffer and fmt::format_to.
The library also no longer provides the fmt::fmt ALIAS, so define
it in externals/CMakeLists.txt.
Kernel/Threads: Add a new thread status that will allow using a Kernel::Event to put a guest thread to sleep inside an HLE handler until said event is signaled
The only functional change is the error handling of GSP_GPU::ReadHWRegs function. We previously didn't return error codes (not even for success). The new returns were found by reverse engineering the GSP module.
An HLE service function that wants to perform an async operation should put the caller guest thread to sleep using SleepClientThread, passing in a callback to execute when the thread is resumed.
SleepClientThread returns a Kernel::Event that should be signaled to resume the guest thread when the host async operation completes.
Kernel/Threads: Add a new thread status that will allow using a Kernel::Event to put a guest thread to sleep inside an HLE handler until said event is signaled
An HLE service function that wants to perform an async operation should put the caller guest thread to sleep using SleepClientThread, passing in a callback to execute when the thread is resumed.
SleepClientThread returns a ThreadContinuationToken that should be stored and used with ContinueClientThread to resume the guest thread when the host async operation completes.
Copy the IPC command buffer to/from the request context before/after the
handler is invoked. This is part of a move away from using global data
for handling IPC requests.
The old "Interface" class had a few problems such as using free
functions (Which didn't allow you to write the service handler as if it
were a regular class.) which weren't very extensible. (Only received one
parameter with a pointer to the Interface object.)
The new ServiceFramework aims to solve these problems by working with
member functions and passing a generic context struct as parameter. This
struct can be extended in the future without having to update all
existing service implementations.
