TestThreadInstrumentation: emit the EXIT event sooner

```
  1) Failure:
TestThreadInstrumentation#test_thread_instrumentation [/tmp/ruby/src/trunk-repeat20-asserts/test/-ext-/thread/test_instrumentation_api.rb:33]:
Call counters[4]: [3, 4, 4, 4, 0].
Expected 0 to be > 0.
```

We fire the EXIT hook after the call to `thread_sched_to_dead` which
mean another thread might be running before the `EXIT` hook have been
executed.

1 files changed, 0 insertions, 1 deletions

diff --git a/thread.c b/thread.c
index d62653679a..c229d4df6c 100644
--- a/thread.c
+++ b/thread.c
@@ -635,7 +635,6 @@ thread_do_start(rb_thread_t *th)
 }
 
 void rb_ec_clear_current_thread_trace_func(const rb_execution_context_t *ec);
-#define thread_sched_to_dead thread_sched_to_waiting
 
 static int
 thread_start_func_2(rb_thread_t *th, VALUE *stack_start)