* einfo.ads: Minor reformatting

	* exp_ch5.adb: Add comment for previous.change

	* ali.adb: New interface for extended typeref stuff.

	* ali.ads: New interface for typeref stuff.

	* checks.adb (Apply_Alignment_Check): New procedure.

	* debug.adb: Add -gnatdM for modified ALI output

	* exp_pakd.adb (Known_Aligned_Enough): Replaces Known_Aligned_Enough.

	* lib-xref.adb: Extend generation of <..> notation to cover
	subtype/object types. Note that this is a complete rewrite,
	getting rid of the very nasty quadratic algorithm previously
	used for derived type output.

	* lib-xref.ads: Extend description of <..> notation to cover
	subtype/object types. Uses {..} for these other cases.
	Also use (..) for pointer types.

	* sem_util.adb (Check_Potentially_Blocking_Operation): Slight cleanup.

	* exp_pakd.adb: Minor reformatting.  Note that prevous RH should say:
	(Known_Aligned_Enough): Replaces Must_Be_Aligned.

From-SVN: r47896