[K/N][Runtime] Switch thread states in termination handlers

kotlin-native/runtime/src/main/cpp/Memory.h

@@ -388,10 +388,11 @@ public:
 namespace kotlin {
 namespace mm {
 
-// Returns the MemoryState for the current thread. The runtime must be initialized.
+// Returns the MemoryState for the current thread.
+// If the memory subsystem isn't initialized for the current thread, returns nullptr.
 // Try not to use it very often, as (1) thread local access can be slow on some platforms,
 // (2) TLS gets deallocated before our thread destruction hooks run.
-MemoryState* GetMemoryState();
+MemoryState* GetMemoryState() noexcept;
 
 } // namespace mm