* sem_prag.adb (Analyze_Pragma, case Validity_Checks): do not treat as
a configuration pragma, it is now legal wherever a pragma can appear.
From-SVN: r47624
* einfo.adb (Has_Pragma_Pure_Function): New flag.
Fix problem that stopped ceinfo from working
* einfo.ads (Has_Pragma_Pure_Function): New flag.
* sem_prag.adb (Pure_Function): Set new flag Has_Pragma_Pure_Function.
From-SVN: r47614
* sem_prag.adb: (Analyze_Pragma, case External): If entity is a
constant, do not indicate possible modification, so that gigi can
treat it as a bona fide constant.
From-SVN: r46168
