bfd_elf_sym_name_raw

Many uses of bfd_elf_sym_name report errors.  They ought to not return
a NULL, as was the case prior to commit 68bbe1183379.  Introduce a new
function for cases where we'd like to know there is a problem with a
symbol st_name.

	* elf-bfd.h  (bfd_elf_sym_name_raw): Declare.
	* elf.c (bfd_elf_sym_name_raw): New function.
	(bfd_elf_sym_name): Revert to behaviour prior to 68bbe1183379,
	but returning "<null>" rather than "(null)" for st_name errors.
	(group_signature): Use bfd_elf_sym_name_raw.
	* elfcode.h (elf_slurp_symbol_table): Likewise.
	* elf32-i386.c (elf_i386_scan_relocs): Whitespace.
4 files changed