Unable to build x86 hosted debugger for ARM Linux, due to missing target

Unable to build x86 hosted debugger for ARM Linux, due to missing target
dependencies.  Created ARM Linux specific arm-linux-tdep.c file and moved
missing code into it from arm-linux-nat.c.

2000-04-05  Scott Bambrough <scottb@netwinder.org>

	* arm-linux-tdep.c: New file.
	* arm-linux-nat.c (fetch_fpregs): Remove unused code.
	  (arm_get_longjmp_target): Moved it and all defines
	  it uses to arm-linux-tdep.c.
	  (arm_linux_extract_return_value): Moved to
	  arm-linux-tdep.c.
	* config/arm/linux.mt: Add arm-linux-tdep.c to TDEPFILES.