libnm: reorder fields in NMIPAddress/NMIPRoute struct

Order the fields by their size, to minimize the alignment gaps.
I guess, that doesn't matter because the alignment of the heap
allocation is larger than what we can safe here. Still, there is
on reason to do it any other way.

Also, it's not possible via API to set family/prefix to values outside
their range, so an 8bit integer is always sufficient. And we don't want
that invariant to change. We don't ever want to allow the caller to set
values that are clearly invalid, and will assert against that early (g_return()).
Point is, we can do this and there is no danger of future problems.
And even if we will support larger values, it's all an implementation
detail anyway.

src/libnm-core-impl/nm-setting-ip-config.c

@@ -169,9 +169,10 @@ G_DEFINE_BOXED_TYPE(NMIPAddress, nm_ip_address, nm_ip_address_dup, nm_ip_address
 struct NMIPAddress {
     guint refcount;
 
-    char *address;
+    gint8  family;
-    int   prefix, family;
+    guint8 prefix;
 
+    char       *address;
     GHashTable *attributes;
 };
 
@@ -608,13 +609,14 @@ G_DEFINE_BOXED_TYPE(NMIPRoute, nm_ip_route, nm_ip_route_dup, nm_ip_route_unref)
 struct NMIPRoute {
     guint refcount;
 
-    int    family;
+    gint8  family;
-    char  *dest;
+    guint8 prefix;
-    guint  prefix;
-    char  *next_hop;
-    gint64 metric;
 
+    char       *dest;
+    char       *next_hop;
     GHashTable *attributes;
+
+    gint64 metric;
 };
 
 /**