[Ada] Cleanup order of Nkind declarations in Sinfo

[Arnaud Charlet]

This is an internal cleanup, no functional effect, no test

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

2013-01-04  Robert Dewar  <de...@adacore.com>

        * sinfo.ads: Clean up order of N_xxx subtypes


Index: sinfo.ads
===================================================================
--- sinfo.ads   (revision 194887)
+++ sinfo.ads   (working copy)
@@ -7638,6 +7638,12 @@
       N_Function_Call,
       N_Procedure_Call_Statement,
 
+      --  N_Subexpr, N_Has_Etype, N_Raise_xxx_Error
+
+      N_Raise_Constraint_Error,
+      N_Raise_Program_Error,
+      N_Raise_Storage_Error,
+
       --  N_Subexpr, N_Has_Etype
 
       N_Explicit_Dereference,
@@ -7648,15 +7654,6 @@
       N_Null,
       N_Qualified_Expression,
       N_Quantified_Expression,
-
-      --  N_Raise_xxx_Error, N_Subexpr, N_Has_Etype
-
-      N_Raise_Constraint_Error,
-      N_Raise_Program_Error,
-      N_Raise_Storage_Error,
-
-      --  N_Subexpr, N_Has_Etype
-
       N_Aggregate,
       N_Allocator,
       N_Case_Expression,