[Ada] Fix handling of gnat check/test commands

[Pierre-Marie de Rodat]

These days, <prefix>gnat check should always call gnatcheck
[--target=prefix], same for gnat test.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * gnatcmd.adb: Fix handling of check and test commands.
diff --git a/gcc/ada/gnatcmd.adb b/gcc/ada/gnatcmd.adb
--- a/gcc/ada/gnatcmd.adb
+++ b/gcc/ada/gnatcmd.adb
@@ -472,6 +472,15 @@ begin
 
          Program := new String'(Command_List (The_Command).Unixcmd.all);
 
+      elsif The_Command in Check | Test then
+         Program := new String'(Command_List (The_Command).Unixcmd.all);
+         Find_Program_Name;
+
+         if Name_Len > 5 then
+            First_Switches.Append
+              (new String'
+                 ("--target=" & Name_Buffer (1 .. Name_Len - 5)));
+         end if;
       else
          Program :=
            Program_Name (Command_List (The_Command).Unixcmd.all, "gnat");
@@ -481,13 +490,7 @@ begin
          --  instead of gnatmake/gnatclean.
          --  Ditto for gnatname -> gprname and gnatls -> gprls.
 
-         if The_Command = Make
-           or else The_Command = Compile
-           or else The_Command = Bind
-           or else The_Command = Link
-           or else The_Command = Clean
-           or else The_Command = Name
-           or else The_Command = List
+         if The_Command in Make | Compile | Bind | Link | Clean | Name | List
          then
             declare
                Switch        : String_Access;
@@ -588,23 +591,23 @@ begin
       end if;
 
       --  For FIND and XREF, look for switch -P. If it is specified, then
-      --  report an error indicating that the command is no longer supporting
-      --  project files.
+      --  report an error indicating that the command does not support project
+      --  files.
 
-      if The_Command = Find or else The_Command = Xref then
+      if The_Command in Find | Xref then
          declare
             Argv : String_Access;
          begin
             for Arg_Num in 1 .. Last_Switches.Last loop
                Argv := Last_Switches.Table (Arg_Num);
 
-               if Argv'Length >= 2 and then
-                  Argv (Argv'First .. Argv'First + 1) = "-P"
+               if Argv'Length >= 2
+                 and then Argv (Argv'First .. Argv'First + 1) = "-P"
                then
                   if The_Command = Find then
-                     Fail ("'gnat find -P' is no longer supported;");
+                     Fail ("'gnat find -P' is not supported;");
                   else
-                     Fail ("'gnat xref -P' is no longer supported;");
+                     Fail ("'gnat xref -P' is not supported;");
                   end if;
                end if;
             end loop;