introduce struct `rb_native_thread`

`rb_thread_t` contained `native_thread_data_t` to represent
thread implementation dependent data. This patch separates
them and rename it `rb_native_thread` and point it from
`rb_thraed_t`.

Now, 1 Ruby thread (`rb_thread_t`) has 1 native thread (`rb_native_thread`).

1 files changed, 7 insertions, 2 deletions

diff --git a/thread_win32.h b/thread_win32.h
index 95cbe7c984..12aef02728 100644
--- a/thread_win32.h
+++ b/thread_win32.h
@@ -26,9 +26,14 @@ struct rb_thread_cond_struct {
     struct cond_event_entry *prev;
 };
 
-typedef struct native_thread_data_struct {
+struct rb_native_thread {
+    HANDLE thread_id;
     HANDLE interrupt_event;
-} native_thread_data_t;
+};
+
+struct rb_thread_sched_item {
+    char dmy;
+};
 
 struct rb_thread_sched {
     HANDLE lock;