[Ada] Fix irregular output with -gnatRm

[Ada] Fix irregular output with -gnatRm

The information displayed by -gnatRm was using slightly different naming
and formatting conventions than the rest of the -gnatR information with
no justification, so this adjusts it for the sake of consistency.

For the following package:

package P is

  function F (I : Integer) return Integer;

  type Rec is limited record
    I : Integer;
  end record;

  procedure P1 (R : Rec; I : out Integer);

  procedure P2 (R : Rec; I : out Integer);
  pragma Linker_Section (P2, ".my_section");

  package Inner is

    procedure P3;

  end Inner;

end P;

package body P is

  function F (I : Integer) return Integer is
  begin
    return I;
  end;

  procedure P1 (R : Rec; I : out Integer) is
  begin
    I := R.I;
  end;

  procedure P2 (R : Rec; I : out Integer) is
  begin
    I := R.I;
  end;

  package body Inner is

     procedure P3 is
     begin
       null;
     end;

  end Inner;

end P;

the output of -gnatRm must be:

Representation information for unit P (body)
--------------------------------------------

Representation information for unit P (spec)
--------------------------------------------

function F declared at p7.ads:3:12
convention : Ada
   I : passed by copy
returns by copy

for Rec'Size use 32;
for Rec'Alignment use 4;
for Rec use record
   I at 0 range  0 .. 31;
end record;

procedure P1 declared at p7.ads:9:13
convention : Ada
   R : passed by reference
   I : passed by copy

procedure P2 declared at p7.ads:11:13
convention : Ada
   R : passed by reference
   I : passed by copy
pragma Linker_Section (P2, ".my_section");

procedure Inner.P3 declared at p7.ads:16:15
convention : Ada

2018-05-29  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* repinfo.adb (List_Entities): Do not list the Linker_Section for
	subprograms here...
	(List_Mechanisms): ...but here instead.  Use consistent name output
	and formatting conventions.

From-SVN: r260861