Port various minor changes from yuzu PRs (#4725)

* common/thread: Remove unused functions

Many of these functions are carried over from Dolphin (where they aren't
used anymore). Given these have no use (and we really shouldn't be
screwing around with OS-specific thread scheduler handling from the
emulator, these can be removed.

The function for setting the thread name is left, however, since it can
have debugging utility usages.

* input_common/sdl: Use a type alias to shorten declaration of GetPollers

Just makes the definitions a little bit more tidy.

* input_common/sdl: Correct return values within implementations of GetPollers()

In both cases, we weren't actually returning anything, which is
undefined behavior.

* yuzu/debugger/graphics_surface: Fill in missing surface format listings

Fills in the missing surface types that were marked as unknown. The
order corresponds with the TextureFormat enum within
video_core/texture.h.

We also don't need to all of these strings as translatable (only the
first string, as it's an English word).

* yuzu/debugger/graphics_surface: Clean up connection overload deduction

We can utilize qOverload with the signal connections to make the
function deducing a little less ugly.

* yuzu/debugger/graphics_surface: Tidy up SaveSurface

- Use QStringLiteral where applicable.

- Use const where applicable

- Remove unnecessary precondition check (we already assert the pixbuf
  being non null)

* yuzu/debugger/graphics_surface: Display error messages for file I/O errors

* core: Add missing override specifiers where applicable

Applies the override specifier where applicable. In the case of
destructors that are  defaulted in their definition, they can
simply be removed.

This also removes the unnecessary inclusions being done in audin_u and
audrec_u, given their close proximity.

* kernel/thread: Make parameter of GetWaitObjectIndex() const qualified

The pointed to member is never actually modified, so it can be made
const.

* kernel/thread: Avoid sign conversion within GetCommandBufferAddress()

Previously this was performing a u64 + int sign conversion. When dealing
with addresses, we should generally be keeping the arithmetic in the
same signedness type.

This also gets rid of the static lifetime of the constant, as there's no
need to make a trivial type like this potentially live for the entire
duration of the program.

* kernel/codeset: Make CodeSet's memory data member a regular std::vector

The use of a shared_ptr is an implementation detail of the VMManager
itself when mapping memory. Because of that, we shouldn't require all
users of the CodeSet to have to allocate the shared_ptr ahead of time.
It's intended that CodeSet simply pass in the required direct data, and
that the memory manager takes care of it from that point on.

This means we just do the shared pointer allocation in a single place,
when loading modules, as opposed to in each loader.

* kernel/wait_object: Make ShouldWait() take thread members by pointer-to-const

Given this is intended as a querying function, it doesn't make sense to
allow the implementer to modify the state of the given thread.

src/common/thread.cpp

@@ -27,18 +27,6 @@ namespace Common {
 
 #ifdef _MSC_VER
 
-void SetThreadAffinity(std::thread::native_handle_type thread, u32 mask) {
-    SetThreadAffinityMask(thread, mask);
-}
-
-void SetCurrentThreadAffinity(u32 mask) {
-    SetThreadAffinityMask(GetCurrentThread(), mask);
-}
-
-void SwitchCurrentThread() {
-    SwitchToThread();
-}
-
 // Sets the debugger-visible name of the current thread.
 // Uses undocumented (actually, it is now documented) trick.
 // http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/html/vxtsksettingthreadname.asp
@@ -70,31 +58,6 @@ void SetCurrentThreadName(const char* name) {
 
 #else // !MSVC_VER, so must be POSIX threads
 
-void SetThreadAffinity(std::thread::native_handle_type thread, u32 mask) {
-#ifdef __APPLE__
-    thread_policy_set(pthread_mach_thread_np(thread), THREAD_AFFINITY_POLICY, (integer_t*)&mask, 1);
-#elif (defined __linux__ || defined __FreeBSD__) && !(defined ANDROID)
-    cpu_set_t cpu_set;
-    CPU_ZERO(&cpu_set);
-
-    for (int i = 0; i != sizeof(mask) * 8; ++i)
-        if ((mask >> i) & 1)
-            CPU_SET(i, &cpu_set);
-
-    pthread_setaffinity_np(thread, sizeof(cpu_set), &cpu_set);
-#endif
-}
-
-void SetCurrentThreadAffinity(u32 mask) {
-    SetThreadAffinity(pthread_self(), mask);
-}
-
-#ifndef _WIN32
-void SwitchCurrentThread() {
-    usleep(1000 * 1);
-}
-#endif
-
 // MinGW with the POSIX threading model does not support pthread_setname_np
 #if !defined(_WIN32) || defined(_MSC_VER)
 void SetCurrentThreadName(const char* name) {