re PR tree-optimization/43984 (PRE misses full-redundancies, inserts into loops)

re PR tree-optimization/43984 (PRE misses full-redundancies, inserts into loops)

	PR tree-optimization/43984

	* tree-ssa-pre.c (inserted_phi_names): Remove.
	(inserted_exprs): Change to bitmap.
	(create_expression_by_pieces): Set bits, don't append to vector.
	(insert_into_preds_of_block): Don't handle inserted_phi_names.
	(eliminate): Don't look at inserted_phi_names, remove deleted
	insns from inserted_exprs.
	(remove_dead_inserted_code): Adjust to use bitmaps instead of
	vectors.
	(init_pre, fini_pre): Allocate and free bitmaps.
	(execute_pre): Insert insns on edges before elimination.

testsuite/
	* gfortran.dg/pr43984.f90: New test.

From-SVN: r159106