bfd_get_relocated_section_contents allow NULL data buffer

bfd_get_relocated_section_contents allow NULL data buffer

This patch removes the bfd_malloc in default_indirect_link_order and
bfd_simple_get_relocated_section_contents, pushing the allocation down
to bfd_get_relocated_section_contents.  The idea is to make use of the
allocation done with sanity checking in bfd_get_full_section_contents,
which is called by bfd_generic_get_relocated_section_contents.

Doing this exposed a bug in bfd_get_full_section_contents.  With
relaxation it is possible that an input section rawsize is different
to the section size.  In that case we want to use the larger of
rawsize (the on-disk size for input sections) and size.

	* reloc.c (bfd_generic_get_relocated_section_contents),
	* reloc16.c (bfd_coff_reloc16_get_relocated_section_contents),
	* coff-alpha.c (alpha_ecoff_get_relocated_section_contents),
	* coff-sh.c (sh_coff_get_relocated_section_contents),
	* elf-m10200.c (mn10200_elf_get_relocated_section_contents),
	* elf-m10300.c (mn10300_elf_get_relocated_section_contents),
	* elf32-avr.c (elf32_avr_get_relocated_section_contents),
	* elf32-cr16.c (elf32_cr16_get_relocated_section_contents),
	* elf32-crx.c (elf32_crx_get_relocated_section_contents),
	* elf32-h8300.c (elf32_h8_get_relocated_section_contents),
	* elf32-nds32.c (nds32_elf_get_relocated_section_contents),
	* elf32-sh.c (sh_elf_get_relocated_section_contents),
	* elfxx-mips.c (_bfd_elf_mips_get_relocated_section_contents):
	Handle NULL data buffer.
	* bfd.c (bfd_get_section_alloc_size): New function.
	* bfd-in2.h: Regenerate.
	* compress.c (bfd_get_full_section_contents): Correct section
	malloc size.
	* linker.c (default_indirect_link_order): Don't malloc memory
	here before calling bfd_get_relocated_section_contents.
	* simple.c (bfd_simple_get_relocated_section_contents): Likewise.