os: optimize struct packing for _XtransConnInfo, _host, and auth

- _XtransConnInfo: pack transptr, priv, flags, fd, index, family, port,
  addr, peeraddr, and recv_fds into the first 64-byte cache line (0 holes!).
  Keeps hot connection I/O fields (transptr, priv, flags, fd) in Cacheline 0
  avoiding extra cache lines during request dispatching.
  Reduces total size from 96 to 80 bytes (-16 bytes).
- _host: group family, len, and requested adjacent to each other.
  Reduces size from 32 to 24 bytes (-25%).
- auth: group id and len adjacent to each other.
  Reduces size from 32 to 24 bytes (-25%).

os/Xtransint.h

@@ -112,18 +112,18 @@ struct _XtransConnFd {
 
 struct _XtransConnInfo {
     struct _Xtransport     *transptr;
-    int		index;
     char	*priv;
     int		flags;
     int		fd;
-    char	*port;
+    int		index;
     int		family;
+    char	*port;
     char	*addr;
-    int		addrlen;
     char	*peeraddr;
-    int		peeraddrlen;
     struct _XtransConnFd        *recv_fds;
     struct _XtransConnFd        *send_fds;
+    int		addrlen;
+    int		peeraddrlen;
 };
 
 #define XTRANS_OPEN_COTS_CLIENT       1

os/access.c

@@ -215,9 +215,9 @@ static Bool NewHost(int /*family */ ,
 typedef struct _host {
     short family;
     short len;
+    int requested;
     unsigned char *addr;
     struct _host *next;
-    int requested;
 } HOST;
 
 #define MakeHost(h,l)	(h)=calloc(1, sizeof *(h)+(l));\

os/mitauth.c

@@ -41,9 +41,9 @@ from The Open Group.
 
 static struct auth {
     struct auth *next;
-    unsigned short len;
     char *data;
     XID id;
+    unsigned short len;
 } *mit_auth;
 
 XID