Removed all structure packing directives. Protocol header fields are naturally aligned by design.

(Earlier, the 14-byte ethernet header screwed this up, this had already been fixed by adding two pad bytes.)
Assumption is that compilers do not align with larger-than-sizeof(type) boundaries.
Pre-tag PRE_PACK_REMOVE. Post-tag POST_TAG_REMOVE.

src/netif/ppp/vjbsdhdr.h

@@ -11,7 +11,6 @@
  * pragmatically since otherwise unsigned comparisons can result
  * against negative integers quite easily, and fail in subtle ways.
  */
-PACK_STRUCT_BEGIN
 struct ip
 {
 #if defined(NO_CHAR_BITFIELDS)
@@ -39,7 +38,6 @@ struct ip
 	u_short	ip_sum;					/* checksum */
 	struct	in_addr ip_src,ip_dst;	/* source and dest address */
 };
-PACK_STRUCT_END
 
 typedef u32_t tcp_seq;
 
@@ -47,7 +45,6 @@ typedef u32_t tcp_seq;
  * TCP header.
  * Per RFC 793, September, 1981.
  */
-PACK_STRUCT_BEGIN
 struct tcphdr  
 {
 	u_short	th_sport;		/* source port */
@@ -71,6 +68,5 @@ struct tcphdr
 	u_short	th_sum;			/* checksum */
 	u_short	th_urp;			/* urgent pointer */
 };
-PACK_STRUCT_END
 
 #endif /* VJBSDHDR_H */