* doc/c-tree.texi (Expressions): Document FLOOR_DIV_EXPR,
	CEIL_DIV_EXPR, ROUND_DIV_EXPR, FLOOR_MOD_EXPR, CEIL_MOD_EXPR,
	ROUND_MOD_EXPR, EXACT_DIV_EXPR.  Improve documentation of
	TRUNC_DIV_EXPR, TRUNC_MOD_EXPR and comparison operations.
	Add missing (but documented) tree nodes to the index.

From-SVN: r82467