TORONTO — A man clad in black fired a handgun into restaurants and cafes in a bustling Toronto neighborhood, killing a 10-year-old girl and an 18-year-old woman and wounding 13 others in an attack that has shaken the confidence of many in the normally safe city. The mass shooting late Sunday in Toronto’s Greektown district came just three months after a van struck and killed 10 people in an apparent attack directed toward women. Police declined to release the name of the 29-year-old gunman from Toronto who died after an exchange of fire with police. Police Chief Mark Saunders said he would not speculate on a motive but did not rule out terrorism.