Fix unbelievably broken counting of native frames

Author: noahbkim

src/native_stack_trace.rs

@@ -96,15 +96,13 @@ impl NativeStack {
 
                         // Merge all python frames until we hit one with `is_entry`.
                         while python_frame_index < frames.len() {
+                            let is_entry = frames[python_frame_index].is_entry;
                             merged.push(frames[python_frame_index].clone());
-
-                            if frames[python_frame_index].is_entry {
+                            python_frame_index += 1;
+                            if is_entry {
                                 break;
                             }
-
-                            python_frame_index += 1;
                         }
-                        python_frame_index += 1;
                     }
                 }
             };