Fix: add rb_vm_rewind_cfp to blocking_operation_wait EC_PUSH_TAG

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: samuel-williams-shopify

scheduler.c

@@ -1119,11 +1119,15 @@ VALUE rb_fiber_scheduler_blocking_operation_wait(VALUE scheduler, void* (*functi
     VALUE result = Qundef;
     enum ruby_tag_type tag_state;
     rb_execution_context_t *ec = GET_EC();
+    rb_control_frame_t *volatile cfp = ec->cfp;
 
     EC_PUSH_TAG(ec);
     if ((tag_state = EC_EXEC_TAG()) == TAG_NONE) {
         result = rb_funcall(scheduler, id_blocking_operation_wait, 1, blocking_operation);
     }
+    else {
+        rb_vm_rewind_cfp(ec, cfp);
+    }
     EC_POP_TAG();
 
     // The scheduler's blocking_operation_wait hook has returned (or raised).