The bytecode generator currently uses the wrong catch prediction in
the desugaring for for-of loops. This leads to unexpected pauses in
DevTools when 'pause on uncaught exceptions' is enabled, e.g. for throwing generators.
Specifically the call to .next of the iterator is unconditionally
marked as 'uncaught' instead of using the surrounding catch
prediction. Similarly, in the desugared "finally" block we call
.return which can also throw.
Note that if both the loop body and the ".return" throws, the
exception from ".return" is caught and only the loop body exception
is re-thrown. We still pause on both throw sites since we can't
detect this case statically.
R=leszeks@chromium.org
Bug: chromium:1270780
Change-Id: I2e642ef3fbfcfc6ad19e92cf611188801ebf2450
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4146420
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/main@{#85164}
