Fix problem where -relax could reorder multiple consecutive sets of the

Fix problem where -relax could reorder multiple consecutive sets of the
same register:
	* coff-sh.c (USES1_REG, USES2_REG, SETS1_REG, SETS2_REG,
	USESF1_REG, USESF2_REG, SETSF1_REG, SETSF2_REG): New macros.
	* (sh_insn_sets_reg, sh_insn_sets_freg): New prototypes.
	* (sh_insn_sets_reg, sh_insn_uses_or_sets_reg, sh_insns_sets_freg,
	sh_insns_uses_or_sets_freg): New functions.
	* (sh_insn_uses_reg, sh_insn_uses_freg): Use new macros.
	* (sh_insns_conflict): Use new functions and new macros to
	detect conflicts when two instructions both set same integer registers,
	both set same fp register, and both set special register.