Shares of AMC Entertainment AMC.N reversed sharp gains to fall 5.8% after launching its second share issue in three days. By Shashank Nayar June 3 (Reuters) - Wall Street's main indexes were set to drop at the open on Thursday as investors weighed data indicating a pick up in jobs growth for cues on the trajectory of an economic recovery and inflation. Concerns over a labor shortage fueling inflationary pressures have raised fears that the Federal Reserve would pare back its crisis support sooner than expected, despite central bank officials' reassurances to the contrary.