MacOS: Fixes configuration hang; bump MacOS SDK.

Removed conditional use of std::mutex instead of std::shared_mutex on MacOS.

Because MacOS < 10.12 did not support std::shared_mutex, a previous commit
naïvely substituted std::mutex, which does not have the same behavior.

Reverses PR #8273, which substitues std::mutex for std::shared_mutex on
macOS, and results in several bugs that seem to only affect MacOS

- https://bugs.dolphin-emu.org/issues/11919
- https://bugs.dolphin-emu.org/issues/11842
- https://bugs.dolphin-emu.org/issues/11845

This change eliminates conditional code for MacOS in the core configuration
layer code and enables the use of modern language features that are more
secure and thread-safe.

CMakeLists.txt

@@ -5,7 +5,10 @@ cmake_minimum_required(VERSION 3.10)
 set(CMAKE_OSX_ARCHITECTURES "x86_64")
 # Minimum OS X version.
 # This is inserted into the Info.plist as well.
-set(CMAKE_OSX_DEPLOYMENT_TARGET "10.10.0" CACHE STRING "")
+
+# MacOS prior to 10.12 did not fully support C++17, which is used to
+# handle configuration options
+set(CMAKE_OSX_DEPLOYMENT_TARGET "10.12.0" CACHE STRING "")
 
 project(dolphin-emu)
 

Source/Core/Common/Config/Config.cpp

@@ -5,11 +5,7 @@
 #include <algorithm>
 #include <list>
 #include <map>
-#if __APPLE__
-#include <mutex>
-#else
 #include <shared_mutex>
-#endif
 
 #include "Common/Config/Config.h"
 
@@ -21,19 +17,10 @@ static Layers s_layers;
 static std::list<ConfigChangedCallback> s_callbacks;
 static u32 s_callback_guards = 0;
 
-// Mac supports shared_mutex since 10.12 and we're targeting 10.10,
-// so only use unique locks there...
-#if __APPLE__
-static std::mutex s_layers_rw_lock;
-
-using ReadLock = std::unique_lock<std::mutex>;
-using WriteLock = std::unique_lock<std::mutex>;
-#else
 static std::shared_mutex s_layers_rw_lock;
 
 using ReadLock = std::shared_lock<std::shared_mutex>;
 using WriteLock = std::unique_lock<std::shared_mutex>;
-#endif
 
 void AddLayerInternal(std::shared_ptr<Layer> layer)
 {