All laws related to attempted suicide in the State of New York were repealed before 1964. If the law had existed before then, it was never used.
Any laws against suicide that may have existed were repealed by the State of New York prior to 1964.
It should be emphasized that suicide is not against the law in most parts of the United States of America. According to written reports from the Attorney General of each of the states (in 1964), there are only nine states [...] in which suicide is a crime.
In recent times, two states (Nevada, New York) repealed such laws, stating in effect that suicide is a grave social wrong, but there is no way to punish it.
In addition to the fact that all laws regarding suicide were removed, and the death penalty hasn't existed in NY since 2007 (see also Oddthinking's answer), there has never been an instance of someone being executed for attempted suicide, reckless endangerment, or anything that could be construed as "jumping off a building" in the State of New York.
Wikipedia has a list of every person executed for crimes in the State of New York. Since 1800, the only persons on the list who were executed for something other than murder or conspiracy to murder are
All other executions on this list were for murder or conspiracy to murder.