[ast-optimizer-branch] Merged mainline into branch as of 2002-06-02

[Diego Novillo]

Bootstrapped and regression tested on x86.

Some minor tweaks were necessary to account for the new global
last_basic_block:

	* tree-cfg.c (delete_bb): Rename to tree_delete_bb.  Update callers.
	(tree_find_basic_blocks): Initializer last_basic_block.
	(create_bb): Update last_basic_block after creating a new block.
	(tree_cleanup_cfg): Delete unreachable blocks by traversing the
	linked list, not the array.  Update comments.
	(delete_bb): Update comments.
	(tree_dump_cfg): Also show last_basic_block.
	* tree-ssa.c (tree_build_ssa): Use last_basic_block instead of
	n_basic_blocks to allocate dominator arrays.
	(insert_phi_terms): Ditto.
	(search_fud_chains): User FOR_EACH_BB to look for dominator
	children.


Diego.