[A64/Function] Initialize macOS JIT threads before thunk

- Add ARM64 macOS thread-local JIT init using pthread_jit_write_protect_np

- Ensure CallImpl enables execute mode before host->guest thunk

src/xenia/cpu/backend/a64/a64_function.cc

@@ -9,10 +9,31 @@
 
 #include "xenia/cpu/backend/a64/a64_function.h"
 
+#ifdef XE_PLATFORM_MAC
+#include <mach/mach.h>
+#include <mach/mach_vm.h>
+#include <mach/vm_map.h>
+#include <pthread.h>
+#endif
+
+#include "xenia/base/logging.h"
 #include "xenia/cpu/backend/a64/a64_backend.h"
 #include "xenia/cpu/processor.h"
 #include "xenia/cpu/thread_state.h"
 
+#if XE_PLATFORM_MAC && defined(__aarch64__)
+thread_local bool jit_thread_initialized = false;
+
+// Initialize JIT execution for the current thread
+static void InitializeJITThread() {
+  if (!jit_thread_initialized) {
+    // Ensure this thread can execute JIT code by setting execute mode
+    pthread_jit_write_protect_np(1);  // Enable execute, disable write
+    jit_thread_initialized = true;
+  }
+}
+#endif
+
 namespace xe {
 namespace cpu {
 namespace backend {
@@ -31,11 +52,20 @@ void A64Function::Setup(uint8_t* machine_code, size_t machine_code_length) {
 }
 
 bool A64Function::CallImpl(ThreadState* thread_state, uint32_t return_address) {
+#if XE_PLATFORM_MAC && defined(__aarch64__)
+  // Initialize JIT execution for this thread
+  // This ensures pthread_jit_write_protect_np is set correctly for execution
+  InitializeJITThread();
+#endif
+
   auto backend =
       reinterpret_cast<A64Backend*>(thread_state->processor()->backend());
   auto thunk = backend->host_to_guest_thunk();
+
+  // Make the actual thunk call
   thunk(machine_code_, thread_state->context(),
         reinterpret_cast<void*>(uintptr_t(return_address)));
+
   return true;
 }