fix strip & objcopy bug with foreign linker

[Nick Clifton]

Hi Nathan,

 > 2008-11-11  Nathan Sidwell  <nathan@codesourcery.com>
 >
 > 	bfd/
 > 	* elf.c (assign_file_positions_for_load_sections): Use
 > header_size
 > 	to avoid moving the load address of file headers.
 > 	(assign_file_positions_for_load_sections): Set header_size for
 > 	segments containing the file header.
 >
 > 	include/elf/
 > 	* internal.h (struct elf_segment_map): Add header_size field.

Approved and applied.  Note I made one change:

+   if (header_pad < off)

changed to

+   if (header_pad < (bfd_vma) off)

to avoid compile time warnings about a comparison between a signed and 
an unsigned quantity.  (For some targets the file_ptr type is signed).

Cheers
   Nick