* tree-phinode.c (resize_phi_node): Abort when LEN is strictly
	greater than PHI_ARG_CAPACITY.
	(reserve_phi_args_for_new_edge): Initialize the new PHI
	argument to NULL_TREE.  Increment PHI_NUM_ARGS.
	(add_phi_arg): Add a PHI argument to the slot given by
	E->dest_idx.
	(remove_phi_arg_num): Do not write to PHI_ARG_EDGE.
	* tree-flow-inline (phi_arg_from_edge): Return E->dest_idx.
	* tree-ssa.c (ssa_redirect_edge): Check for a missing PHI
	argument by looking at PHI_ARG_DEF.
	(verify_phi_args): Check for a missing PHI argument.  Remove
	the check for duplicate PHI arguments.
	* tree.h (PHI_ARG_EDGE): Redefine in terms of EDGE_PRED.
	(phi_arg_d): Remove e.

From-SVN: r91097