Fix ARM64 MSVC linker problem

Close https://github.com/microsoft/mimalloc/issues/426

src/init.c

@@ -571,7 +571,7 @@ static void mi_process_done(void) {
     return 0;
   }
   typedef int(*_crt_cb)(void);
-  #ifdef _M_X64
+  #if defined(_M_X64) || defined(_M_ARM64)
     __pragma(comment(linker, "/include:" "_mi_msvc_initu"))
     #pragma section(".CRT$XIU", long, read)
   #else