selective.exp xfails

[Ben Elliston]

>>>>> "H" == H J Lu <hjl@lucon.org> writes:

  >> + Why are all Alpha targets XFAILed?

  H> I don't think alpha supports garbage collection.

Okay.

  H> I don't think mips supports garbage collection either.

Really?
 
  ``* Added garbage collection of unused sections, enabled by --gc-sections.
      It does require a bit of backend support; currently implemented are
      arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
      mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
      Others will ignore the option.''

Ben