gdb build fails for i586-linux cross arm-linux

[Philip Blundell <Philip dot Blundell at pobox dot com>]

Hi Scott

Compiling the current GDB on my Intel machine with `--target=arm-linux', I 
get:

gcc -g        -o gdb main.o libgdb.a    ../bfd/libbfd.a ../readline/libreadline.a ../opcodes/libopcodes.a  ../libiberty/libiberty.a -lncurses    ../libgui/src/libgui.a -L/var/tmp/build/binutils-arm/itcl/itcl/unix -litcl3.0 -L/var/tmp/build/binutils-arm/itcl/itk/unix -litk3.0 -L/var/tmp/build/binutils-arm/tix/unix/tk8.0 -ltix4.1.8.0 -L/var/tmp/build/binutils-arm/tk/unix -ltk8.0 -L/var/tmp/build/binutils-arm/tcl/unix -ltcl8.0   -L/usr/X11R6/lib -lX11 -ldl  -lieee -lm -lm  ../libiberty/libiberty.a  -ldl -rdynamic
libgdb.a(values.o): In function `value_being_returned':
/usr/src/sourceware/src/gdb/values.c:1542: undefined reference to `arm_linux_extract_return_value'
libgdb.a(infrun.o): In function `handle_inferior_event':
/usr/src/sourceware/src/gdb/infrun.c:2296: undefined reference to `arm_get_longjmp_target'

These functions are defined in arm-linux-nat.c but required by 
config/arm/tm-linux.h.  Should we create a new arm-linux-tdep.c file for these 
functions, or are they genuinely not useful outside a native environment?

Thanks

p.