ada: List subprogram body entities in scopes

ada: List subprogram body entities in scopes

Add entities of kind E_Subprogram_Body to the list of entities associated
to a given scope. This ensures that representation information is
correctly output for object and type declarations inside these subprogram
bodies. This is useful for outputing that information fron the compiler
with the switch -gnatR, as well as for getting precise representation
information inside GNATprove.

Remove ad-hoc code inside repinfo.adb that retrieved this information
in only some cases.

gcc/ada/

	* exp_ch5.adb (Expand_Iterator_Loop_Over_Container): Skip entities
	of kind E_Subprogram_Body.
	* repinfo.adb (List_Entities): Remove special case for subprogram
	bodies.
	* sem_ch6.adb (Analyze_Subprogram_Body_Helper): List subprogram
	body entities in the enclosing scope.