re PR rtl-optimization/46649 (ICE: in move_bb_info, at sel-sched-ir.c:5080 with -fschedule-insns -fselective-scheduling)

	PR rtl-optimization/46649
	* sel-sched-ir.c (purge_empty_blocks): Unconditionally skip the first
	basic block in the region.

testsuite:
	* g++.dg/opt/pr46649.C: New.

From-SVN: r167854