[Ada] Restore double quotes in debug printouts

A previous change in "Make debug printouts more robust" accidentally
removed double quotes around identifiers in debug printouts. This patch
restores those. So for example, we have:

       Prev_Entity = Node gcc-mirror#10 N_Defining_Identifier "foo" (Entity_Id=795)

and not:

       Prev_Entity = Node gcc-mirror#10 N_Defining_Identifier foo (Entity_Id=795)

This affects the output of -gnatdt, and certain calls normally done from
gdb.

gcc/ada/

	* namet.ads, namet.adb (Write_Name_For_Debug): Add Quote
	parameter to allow conditional addition of quotes. Note that
	some calls to Write_Name_For_Debug, for example for file names,
	shouldn't have quotes, as in some_package.adb:123:45.
	* treepr.adb (Print_Name): Add double quotes around the name
	using the above Quote parameters.

gcc/ada/namet.adb

@@ -1570,16 +1570,20 @@ package body Namet is
    -- Write_Name_For_Debug --
    --------------------------
 
-   procedure Write_Name_For_Debug (Id : Name_Id) is
+   procedure Write_Name_For_Debug (Id : Name_Id; Quote : String := "") is
    begin
       if Is_Valid_Name (Id) then
+         Write_Str (Quote);
+
          declare
             Buf : Bounded_String (Max_Length => Natural (Length_Of_Name (Id)));
          begin
             Append (Buf, Id);
             Write_Str (Buf.Chars (1 .. Buf.Length));
          end;
 
+         Write_Str (Quote);
+
       elsif Id = No_Name then
          Write_Str ("<No_Name>");
 

gcc/ada/namet.ads

@@ -433,9 +433,9 @@ package Namet is
    --  Like Write_Name, except that the name written is the decoded name, as
    --  described for Append_Decoded.
 
-   procedure Write_Name_For_Debug (Id : Name_Id);
+   procedure Write_Name_For_Debug (Id : Name_Id; Quote : String := "");
    --  Like Write_Name, except it tries to be robust in the presence of invalid
-   --  data.
+   --  data, and valid names are surrounded by Quote.
 
    function Name_Entries_Count return Nat;
    --  Return current number of entries in the names table

gcc/ada/treepr.adb

@@ -1142,7 +1142,7 @@ package body Treepr is
    procedure Print_Name (N : Name_Id) is
    begin
       if Phase = Printing then
-         Write_Name_For_Debug (N);
+         Write_Name_For_Debug (N, Quote => """");
       end if;
    end Print_Name;