s-atacco.ads, [...]: Protect use of 'Constrained by warnings on/off...

s-atacco.ads, [...]: Protect use of 'Constrained by warnings on/off...

	* s-atacco.ads, a-direio.adb: Protect use of 'Constrained by warnings
	on/off, since this is an obsolescent feature, for which we now generate
	a warning.

	* sem_attr.adb (Analyze_Attribute, case Constrained): Issue warning if
	warning mode is set and obsolescent usage of this attribute occurs.
	(Resolve_Access, case 'Access): Note that GNAT uses the context type to
	disambiguate overloaded prefixes, in accordance with AI-235. GNAT code
	predates, and partly motivates, the adoption of the AI.
	Implement new Ada 2005 attribute Mod

	* exp_attr.adb (Expand_N_Attribute_Reference): Implement Ada 2005
	attribute Mod.

	* par-ch4.adb (P_Name): In Ada 2005 mode, recognize new attribute Mod

	* snames.h, snames.ads, snames.adb: Add entry for No_Dependence for
	pragma restrictions.
	New entry for Ada 2005 attribute Mod.

	* par-prag.adb:
	Add recognition of new pragma Restrictions No_Dependence
	Recognize restriction No_Obsolescent_Features at parse time

	* bcheck.adb: Add circuitry for checking for consistency of
	No_Dependence restrictions.

	* lib-writ.ads, lib-writ.adb: Output new R lines for No_Dependence
	restrictions.

	* restrict.ads, restrict.adb: Add subprograms to deal with
	No_Dependence restrictions.

	* rtsfind.adb: Check that implicit with's do not violate No_Dependence
	restrictions.

	* sem_ch3.adb, sem_ch11.adb, sem_ch13.adb, lib-xref.adb,
	sem_attr.adb: Add check for new restriction No_Obsolescent_Features

	* scn.ads, prj-err.ads, prj-err.adb, ali-util.adb, gprep.adb: Add new
	dummy parameter to scng instantiation.
	Needed for new restriction No_Obsolescent_Features

	* scn.adb: (Obsolescent_Check): New procedure
	Needed for new restriction No_Obsolescent_Features

	* scng.ads, scng.adb: Always allow wide characters in Ada 2005 mode, as
	specified by AI-285, needed for implementation of AI-388 (adding greek
	pi to Ada.Numerics).
	Add new generic formal to scng, needed for new restriction
	No_Obsolescent_Features.

	* s-rident.ads: Add new restriction No_Obsolescent_Features.

	* ali.ads, ali.adb: Adjustments for reading new No_Dependence
	restrictions lines.
	(Scan_ALI): When finding an unexpected character on an R line, raise
	exception Bad_R_Line, instead of calling Fatal_Error, so that, when
	Ignore_Errors is True, default restrictions are set and scanning of the
	ALI file continues with the next line. Also, when Bad_R_Line is raised
	and Ignore_Errors is True, skip to the end of le line.

	* sem_ch10.adb: Check that explicit with's do not violate
	No_Dependence restrictions.
	(Install_Withed_Unit): Add code to implement AI-377 and diagnose
	illegal context clauses containing child units of instance.

	* sem_prag.adb: Processing and checking for new No_Dependence
	restrictions.
	(Analyze_Pragma, case Psect_Object): Call Check_Arg_Is_External_Name to
	analyze and check the External argument.

	* a-numeri.ads: Add greek letter pi as alternative spelling of Pi

From-SVN: r92829