Fix incremental parsing bailout logic #28742
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Incremental parsing is designed to bail out in certain parsing contexts, such as element lists of array literals. The bailout logic does a lot of redundant work before exiting, however, and this can lead to very poor performance in the language service. While investigating a fix for #28540 I experienced language service delays of up to 30 seconds when typing in a file containing a very large array literal. This PR fixes the issue by optimizing the bailout logic.
There are no tests associated with this PR as we don't have suitable infrastructure, but the fix has been experimentally verified.