lib-writ.adb (Write_With_Lines): Factor duplicated code between the cases where a given dependency has a body or not.

2007-04-06  Thomas Quinot  <quinot@adacore.com>

	* lib-writ.adb (Write_With_Lines): Factor duplicated code between the
	cases where a given dependency has a body or not.
	(Write_With_File_Names): New subprogram, common code for the two cases
	above.

From-SVN: r123582