By Asif Shahzad and Syed Raza Hassan ISLAMABAD (Reuters) -Pakistan’s Supreme Court ruled on Thursday that Prime Minister Imran Khan’s move to dissolve parliament was unconstitutional and called for lawmakers to return in two days, a decision that could spell the end of his premiership. The former cricket star had moved to dissolve the lower chamber ahead of a no-confidence vote against him that he had looked destined to lose. The court said in its judgment that the vote would now go ahead. The constitutional crisis has threatened economic and social stability in the nuclear-armed nation of 220…