[RFA] reorganize comp_unit_head for better packing

[Doug Evans]

Simple change.  Ok to check in?

2008-09-23  Doug Evans  <dje@google.com>

	* dwarf2read.c (comp_unit_head): Reorganize for better packing.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.283
diff -u -p -u -p -r1.283 dwarf2read.c
--- dwarf2read.c	15 Sep 2008 15:32:01 -0000	1.283
+++ dwarf2read.c	23 Sep 2008 09:49:15 -0000
@@ -233,9 +236,9 @@ struct comp_unit_head
 {
   unsigned long length;
   short version;
-  unsigned int abbrev_offset;
   unsigned char addr_size;
   unsigned char signed_addr_p;
+  unsigned int abbrev_offset;
 
   /* Size of file offsets; either 4 or 8.  */
   unsigned int offset_size;