unwinder: ignore disabled frames

this can happend when a deopt() call inside the llvm tier throws.
We would catch the exception in order to do some decrefs and than reraise it from the disabled frame.

src/codegen/unwinding.cpp

@@ -462,6 +462,9 @@ bool frameIsPythonFrame(unw_word_t ip, unw_word_t bp, unw_cursor_t* cursor, Pyth
         }
     }
 
+    if (info->getFrameInfo()->isDisabledFrame())
+        return false;
+
     return true;
 }
 

src/core/types.h

@@ -1056,6 +1056,7 @@ struct FrameInfo {
     // Calling disableDeinit makes future deinitFrameMaybe() frames not call deinitFrame().
     // For use by deopt(), which takes over deinit responsibility for its caller.
     void disableDeinit(FrameInfo* replacement_frame);
+    bool isDisabledFrame() const { return back == NO_DEINIT; }
 
     FrameInfo(ExcInfo exc)
         : exc(exc),

src/runtime/frame.cpp

@@ -247,17 +247,18 @@ void FrameInfo::disableDeinit(FrameInfo* replacement_frame) {
 
     // Kinda hacky but maybe worth it to not store any extra bits:
     back = NO_DEINIT;
+    assert(isDisabledFrame());
 }
 
 extern "C" void deinitFrameMaybe(FrameInfo* frame_info) {
     // Note: this has to match FrameInfo::disableDeinit
-    if (frame_info->back != FrameInfo::NO_DEINIT)
+    if (!frame_info->isDisabledFrame())
         deinitFrame(frame_info);
 }
 
 extern "C" void deinitFrame(FrameInfo* frame_info) {
     // This can fire if we have a call to deinitFrame() that should be to deinitFrameMaybe() instead
-    assert(frame_info->back != FrameInfo::NO_DEINIT);
+    assert(!frame_info->isDisabledFrame());
 
     assert(cur_thread_state.frame_info == frame_info);
     cur_thread_state.frame_info = frame_info->back;