Complete making the kernel thread-safe #2 + Fix Shared Memory Implementation

This commit makes the kernel completely thread-safe and fixes an issue that caused libNX games to not work due to an error with KSharedMemory. In addition, implement GroupMutex to allow the kernel threads to run in parallel but still allow them to not overlap with the JNI thread.

app/src/main/cpp/skyline/kernel/svc.h

@@ -110,6 +110,7 @@ namespace skyline {
          * @brief Stalls a thread till a KSyncObject signals or the timeout has ended (https://switchbrew.org/wiki/SVC#svcWaitSynchronization)
          */
         void WaitSynchronization(DeviceState &state);
+
         /**
          * @brief Locks a specified mutex
          */