[Ada] Remove constant arguments

[Ada] Remove constant arguments

gcc/ada/

	* ali.adb (Get_Name): Ignore_Spaces is always False.
	* bindo-graphs.adb (Set_Is_Existing_Source_Target_Relation): Val
	is always True.
	* cstand.adb (New_Standard_Entity): New_Node_Kind is always
	N_Defininig_Identifier.
	* exp_ch3.adb (Predef_Stream_Attr_Spec): For_Body is always
	False.
	* exp_dist.adb (Add_Parameter_To_NVList): RACW_Ctrl is always
	False.
	* gnatls.adb (Add_Directories): Prepend is always False.
	* sem_ch10.adb, sem_ch10.ads (Load_Needed_Body): Do_Analyze is
	always True.
	* sem_ch3.adb, sem_ch3.ads (Process_Range_Expr_In_Decl):
	R_Check_Off is always False.
	* sem_elab.adb: (Info_Variable_Reference): Info_Msg is always
	False, In_SPARK is always True.
	(Set_Is_Traversed_Body, Set_Is_Saved_Construct,
	Set_Is_Saved_Relation): Val is always True.
	* treepr.adb (Visit_Descendant): No_Indent is always False.
	(Print_Node): Fmt does not need such a big scope.