Fix compile time warning messages when compiling binutils with gcc 7.0.1.

Fix compile time warning messages when compiling binutils with gcc 7.0.1.

	PR 21096
bfd	* coffcode.h (coff_write_object_contents): Enlarge size of
	s_name_buf in order to avoid compile time warning about possible
	integer truncation.
	* elf32-nds32.c (nds32_elf_ex9_import_table): Mask off lower
	32-bits of insn value before printing into buffer.

opcodes	* aarch64-opc.c (print_register_list): Ensure that the register
	list index will fir into the tb buffer.
	(print_register_offset_address): Likewise.
	* tic6x-dis.c (print_insn_tic6x): Increase size of func_unit_buf.