einfo.ads (Is_Independent): Document extended usage.

einfo.ads (Is_Independent): Document extended usage.

2015-01-06  Eric Botcazou  <ebotcazou@adacore.com>

	* einfo.ads (Is_Independent): Document extended usage.
	* einfo.adb (Is_Independent): Remove obsolete assertion.
	(Set_Is_Independent): Likewise.
	* sem_prag.adb (Process_Atomic_Shared_Volatile): Rename into...
	(Process_Atomic_Independent_Shared_Volatile): ...this.
	Deal with pragma Independent here.
	(Analyze_Pragma): Adjust
	to above renaming and also invoke it for pragma Independent.
	Adjust comment for Independent_Components.

From-SVN: r219245