[Ada] Fix layout of pragma Inline in generated AST unit

[Pierre-Marie de Rodat via Gcc-patches]

Make the generated nmake.ads unit look more like it was written with
GNAT style rules in mind; semantics is unaffected.

Cleanup related to fix of default initialization in multi-dimensional
arrays, which used to explicitly call the Nmake.Make_Null routine.

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

gcc/ada/

        * gen_il-gen.adb (Put_Make_Decls): Put pragma Inline in a
        dedicated line, so that the current indentation is taken into
        account.
diff --git a/gcc/ada/gen_il-gen.adb b/gcc/ada/gen_il-gen.adb
--- a/gcc/ada/gen_il-gen.adb
+++ b/gcc/ada/gen_il-gen.adb
@@ -2472,7 +2472,8 @@ package body Gen_IL.Gen is
          for T in First_Concrete (Root) .. Last_Concrete (Root) loop
             if T not in N_Unused_At_Start | N_Unused_At_End then
                Put_Make_Spec (S, Root, T);
-               Put (S, ";" & LF & "pragma " & Inline & " (Make_" &
+               Put (S, ";" & LF);
+               Put (S, "pragma " & Inline & " (Make_" &
                     Image_Sans_N (T) & ");" & LF & LF);
             end if;
          end loop;