kern: implement revised IPI/SGI semantics

libraries/libmesosphere/include/mesosphere/arch/arm64/kern_cpu.hpp

@@ -188,6 +188,7 @@ namespace ams::kern::arch::arm64::cpu {
 
     /* Synchronization helpers. */
     NOINLINE void SynchronizeAllCores();
+    void SynchronizeCores(u64 core_mask);
 
     /* Cache management helpers. */
     void StoreCacheForInit(void *addr, size_t size);

libraries/libmesosphere/include/mesosphere/arch/arm64/kern_k_interrupt_name.hpp

@@ -21,11 +21,12 @@ namespace ams::kern::arch::arm64 {
 
         enum KInterruptName : s32 {
             /* SGIs */
-            KInterruptName_ThreadTerminate        = 4,
-            KInterruptName_CacheOperation         = 5,
-            KInterruptName_Scheduler              = 6,
+            KInterruptName_ThreadTerminate        = 0,
+            KInterruptName_CacheOperation         = 1,
+            KInterruptName_Scheduler              = 2,
+            KInterruptName_CoreBarrier            = 3,
 
-            KInterruptName_PerformanceCounter     = 8,
+            KInterruptName_PerformanceCounter     = 4,
 
             /* PPIs */
     #if defined(ATMOSPHERE_BOARD_NINTENDO_NX)