* basic-block.h (struct edge_list): Stucture to maintain a vector
of edges.
(EDGE_INDEX_NO_EDGE, EDGE_INDEX, INDEX_EDGE_PRED_BB, INDEX_EDGE_SUCC_BB,
INDEX_EDGE, NUM_EDGES): New Macros for accessing edge list.
(create_edge_list, free_edge-List, print_edge_list, verify_edge_list):
New function prototypes.
* flow.c (create_edge_list): Function to create an edge list.
(free_edge_list): Discards memory used by an edge list.
(print_edge_list): Debug output showing an edge list.
(verify_edge_list): Internal consistency check for an edge list.
From-SVN: r28732
