[PATCH] Minor cleanup of const_and_copies stack

[PATCH] Minor cleanup of const_and_copies stack

	* tree-ssa-scopedtables.c (const_and_copies::const_and_copies): Remove
	unnecessary constructor.  It's now trivial and implemented inside...
	* tree-ssa-scopedtables.h (const_and_copies): Implement trivial
	constructor.  Add comments to various methods.  Remove unused
	private fields.
	* tree-ssa-dom.c (pass_dominator::execute): Corresponding changes.
	* tree-vrp.c (identify_jump_threads): Likewise.
	* tree-ssa-threadedge.c (thread_through_normal_block): Fix minor
	indentation issues.
	(thread_across_edge): Similarly.
	(record_temporary_equivalences_from_stmts_at_dest): Remove unused
	arguments in constructor call.

From-SVN: r227493