* Makefile.in (m68k_tdep_h): Define.

	* Makefile.in (m68k_tdep_h): Define.
	(abug-rom.o, cpu32bug-rom.o, dbug-rom.o, m68k-tdep.o, m68klinux-nat.o)
	(remote-est.o, rom68k-rom.o): Add $(m68k_tdep_h).
	* m68k-tdep.c: Move register number enum ...
	* m68k-tdep.h: ... to this new file and rename the constants from
	E_* to M68K_*.  All uses changed.
	* config/m68k/tm-m68k.h (D0_REGNUM, A0_REGNUM): Remove definitions.
	* abug-rom.c: Include "m68k-tdep.h".  Use
	M68K_D0_REGNUM/M68K_A0_REGNUM instead of D0_REGNUM/A0_REGNUM.
	* cpu32bug-rom.c: Likewise.
	* dbug-rom.c: Likewise.
	* m68k-tdep.c: Likewise.
	* m68klinux-nat.c: Likewise.
	* remote-est.c: Likewise.
	* rom68k-rom.c: Likewise.
	* config/m68k/tm-linux.h: Likewise.