gnat_rm.texi, [...]: Update documentation.

gnat_rm.texi, [...]: Update documentation.

	* gnat_rm.texi, gnat_ugn.texi,
	doc/gnat_ugn/building_executable_programs_with_gnat.rst,
	doc/gnat_ugn/platform_specific_information.rst,
	doc/gnat_ugn/gnat_and_program_execution.rst,
	doc/gnat_ugn/gnat_utility_programs.rst,
	doc/gnat_ugn/the_gnat_compilation_model.rst,
	doc/gnat_rm/implementation_defined_attributes.rst,
	doc/gnat_rm/the_gnat_library.rst,
	doc/gnat_rm/implementation_defined_pragmas.rst,
	doc/gnat_rm/representation_clauses_and_pragmas.rst,
	doc/gnat_rm/implementation_of_specific_ada_features.rst,
	doc/gnat_rm/implementation_defined_aspects.rst,
	doc/gnat_rm/implementation_defined_characteristics.rst: Update
	documentation.

From-SVN: r247253