* elf32-h8300 (h8_relax_section): Add new relaxation of mov

	* elf32-h8300 (h8_relax_section): Add new relaxation of mov
	@(disp:32,ERx) to mov @(disp:16,ERx).
	(R_H8_DISP32A16): New reloc.
	Comments added and corrected.
	* reloc.c (BFD_RELOC_H8_DISP32A16): New reloc.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.

	* ld.texinfo (H8/300): Add description of relaxation of
	mov @(disp:32,ERx) to mov @(disp:16,ERx).

	* ld-h8300/h8300.exp: Add new relax-7 test on ELF.
	* ld-h8300/relax-2.s: Add other direction and .w/.l variants of
	mov insns.
	* ld-h8300/relax-2.d: Update expected disassembly.
	* ld-h8300/relax-7a.s: New: tests for mov @(disp:32,ERx) -> mov
	@(disp:16,ERx).
	* ld-h8300/relax-7b.s: New: Likewise.
	* ld-h8300/relax-7.d: New: expected disassembly.

	* config/tc-h8300.c (do_a_fix_imm): Add relaxation of mov
	@(disp:32,ERx) to mov @(disp:16,ERx) insns by new reloc
	R_H8_DISP32A16.
	* config/tc-h8300.h: Remove duplicated defines.