This reverts commit 61b5ba7ecf.
Reason for revert: found a counter-example for deep cloning: https://dart-review.googlesource.com/c/sdk/+/70681
Original change's description:
> [vm] Deep clone context when cloning closure
>
> _SyncIterable::iterator clones unerlying sync* closure to create a new
> Iterator using _Closure._clone(). _Closure._clone() was cloning only
> 1 level of context, relying on a particular context structure.
>
> In bytecode, contexts are allocated in a different way, so sync*
> functions could have more then 1 level of contexts. In such case,
> parent contexts were not cloned in _Closure._clone() and were shared
> between Iterator instances.
>
> This CL adds deep cloning of contexts into _Closure._clone() native method
> in order to handle arbitrary number of levels of contexts in a closure.
>
> Fixes language_2/syncstar_yield_test test in bytecode mode.
>
> Change-Id: Ic5ced4c32fc2e21726db76608cd3a7db7e553472
> Reviewed-on: https://dart-review.googlesource.com/70600
> Reviewed-by: Régis Crelier <regis@google.com>
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
TBR=rmacnak@google.com,alexmarkov@google.com,regis@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I9f6116069cbec022ad86ef4cbf6801c603b4ab15
Reviewed-on: https://dart-review.googlesource.com/70700
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Alexander Markov
b97f885d1d