Replace uses of asprintf with xasprintf

Replace uses of asprintf with xasprintf

xasprintf has a nicer interface and behaves like xmalloc as far as
memory is concerned, ie. no need to check a return status and the
program exits with an error on OOM.

binutils/
	* dwarf.c (load_debug_sup_file): Replace asprintf with xasprintf.
	* nm.c (get_elf_symbol_type, get_coff_symbol_type): Likewise.
	* objdump.c (dump_ctf_indent_lines): Likewise.
	* readelf.c (display_lto_symtab, dump_ctf_indent_lines): Likewise.
	* windres.c (main): Likewise.
	* configure.ac: Remove asprintf from AC_CHECK_DECLS.
	* config.in: Regenerate.
	* configure: Regenerate.
gas/
	* config/tc-kvx.c (kvx_emit_single_noop): Simplify.
	* config/tc-riscv.c (md_assemblef): Replace asprintf with xasprintf.
	* read.c (s_nop, do_s_func): Likewise.
	* stabs.c (stabs_generate_asm_func): Likewise.
	(stabs_generate_asm_endfunc): Likewise.
	* configure.ac: Remove asprintf from AC_CHECK_DECLS.
	* config.in: Regenerate.
	* configure: Regenerate.
ld/
	* ldlang.c (lang_leave_overlay_section): Replace xmalloc+sprintf
	with xasprintf.  Localise vars.
	* lexsup.c (parse_args): Replace asprintf with xasprintf.
	* pe-dll.c (make_head, make_tail, make_one): Likewise.
	(make_singleton_name_thunk, make_import_fixup_entry): Likewise.
	(make_runtime_pseudo_reloc): Likewise.
	(pe_create_runtime_relocator_reference): Likewise.
	* configure.ac: Remove asprintf from AC_CHECK_DECLS.
	* config.in: Regenerate.
	* configure: Regenerate.