Cross compiling for ARM: incorrect fx_r_type (8) for fx_subsy != 0

[Daniel Ringwalt]

I am trying to cross compile GMP for the iPhone (arm-apple-darwin),
there is always this error during build:

  tmp-invert_limb.s:56:FATAL:Internal error: incorrect fx_r_type (8)
for fx_subsy != 0 in fix_to_relocation_info()

I am using an Intel Mac, build is successful with native compiling and
cross compiling for powerpc-apple-darwin9.