re PR tree-optimization/47053 (ICE: verify_flow_info failed: BB 2 can not throw but...

re PR tree-optimization/47053 (ICE: verify_flow_info failed: BB 2 can not throw but has an EH edge with -O -fnon-call-exceptions)

	PR tree-optimization/47053
	* tree-ssa-dse.c (need_eh_cleanup): New bitmap.
	(dse_optimize_stmt): Set the appropriate bit in NEED_EH_CLEANUP when
	statements are deleted.
	(tree_ssa_dse): Allocate & free NEED_EH_CLEANUP.  If NEED_EH_CLEANUP
	is nonempty, then purge dead edges and cleanup the CFG.

	PR tree-optimization/47053
	* g++.dg/pr47053.C: New test.

From-SVN: r169123