Add support for the GBZ80 and Z80N variants of the Z80 architecture, and add DWARF...

Add support for the GBZ80 and Z80N variants of the Z80 architecture, and add DWARF debug info support to the Z80 assembler.

	PR 25469
bfd	* archures.c: Add GBZ80 and Z80N machine values.
	* reloc.c: Add BFD_RELOC_Z80_16_BE.
	* coff-z80.c: Add support for new reloc.
	* coffcode.h: Add support for new machine values.
	* cpu-z80.c: Add support for new machine names.
	* elf32-z80.c: Add support for new reloc.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.

binutils* readelf.c (get_machine_flags): Add support for Z80N machine
	number.

gas	* config/tc-z80.c: Add -gbz80 command line option to generate code
	for the GameBoy Z80.  Add support for generating DWARF.
	* config/tc-z80.h: Add support for DWARF debug information
	generation.
	* doc/c-z80.texi: Document new command line option.
	* testsuite/gas/z80/gbz80_all.d: New file.
	* testsuite/gas/z80/gbz80_all.s: New file.
	* testsuite/gas/z80/z80.exp: Run the new tests.
	* testsuite/gas/z80/z80n_all.d: New file.
	* testsuite/gas/z80/z80n_all.s: New file.
	* testsuite/gas/z80/z80n_reloc.d: New file.

include	* coff/internal.h (R_IMM16BE): Define.
	* elf/z80.h (EF_Z80_MACH_Z80N): Define.
	(R_Z80_16_BE): New reloc.

ld	* emulparams/elf32z80.sh: Use z80 emulation.
	* emultempl/z80.em: Make generic to both COFF and ELF Z80 emulations.
	* emultempl/z80elf.em: Delete.
	* testsuite/ld-elf/pr22450.d: Expect to fail for the Z80.
	* testsuite/ld-elf/sec64k.exp: Fix Z80 assembly.
	* testsuite/ld-unique/pr21529.s: Avoid register name conflict.
	* testsuite/ld-unique/unique.s: Likewise.
	* testsuite/ld-unique/unique_empty.s: Likewise.
	* testsuite/ld-unique/unique_shared.s: Likewise.
	* testsuite/ld-unique/unique.d: Updated expected output.
	* testsuite/ld-z80/arch_z80n.d: New file.
	* testsuite/ld-z80/comb_arch_z80_z80n.d: New file.
	* testsuite/ld-z80/labels.s: Add more labels.
	* testsuite/ld-z80/relocs.s: Add more reloc tests.
	* testsuite/ld-z80/relocs_f_z80n.d: New file

opcodes	* z80-dis.c: Add support for GBZ80 opcodes.