[PATCH,HURD] Fix reading core

[Samuel Thibault]

The i386 GNU/Hurd ELF core format actually follows the uaccess gregset_t
array format, not the Mach thread state format.  This fixes gdb reading
it.

* gdb/i386gnu-nat.c (CREG_OFFSET): New macro.
(creg_offset): New array.
(CREG_ADDR): Use creg_offset instead of reg_offset.

--- a/gdb/i386gnu-nat.c.original        2013-02-11 00:46:02.000000000 +0000
+++ b/gdb/i386gnu-nat.c 2013-02-11 00:48:09.000000000 +0000
@@ -56,8 +56,21 @@
   REG_OFFSET (ds), REG_OFFSET (es), REG_OFFSET (fs), REG_OFFSET (gs)
 };
 
+/* Offset to the greg_t location where REG is stored.  */
+#define CREG_OFFSET(reg) (REG_##reg * 4)
+
+/* At CREG_OFFSET[N] is the offset to the greg_t location where
+   the GDB register N is stored.  */
+static int creg_offset[] =
+{
+  CREG_OFFSET (EAX), CREG_OFFSET (ECX), CREG_OFFSET (EDX), CREG_OFFSET (EBX),
+  CREG_OFFSET (UESP), CREG_OFFSET (EBP), CREG_OFFSET (ESI), CREG_OFFSET (EDI),
+  CREG_OFFSET (EIP), CREG_OFFSET (EFL), CREG_OFFSET (CS), CREG_OFFSET (SS),
+  CREG_OFFSET (DS), CREG_OFFSET (ES), CREG_OFFSET (FS), CREG_OFFSET (GS)
+};
+
 #define REG_ADDR(state, regnum) ((char *)(state) + reg_offset[regnum])
-#define CREG_ADDR(state, regnum) ((const char *)(state) + reg_offset[regnum])
+#define CREG_ADDR(state, regnum) ((const char *)(state) + creg_offset[regnum])
 
 
 /* Get the whole floating-point state of THREAD and record the values