Various libgloss problems after recent changes

[Jeff Law]

The fr30-elf and xstormy16-elf ports have been failing to build for 
about a month with this error:

  > fr30-elf-as  -I. -I../../../../..//newlib-cygwin/libgloss/fr30/.. 
-I./.. -idirafter 
../../../../..//newlib-cygwin/libgloss/fr30/../../include  -o crt0.o 
../../../../..//newlib-cygwin/libgloss/fr30/crt0.s
> fr30-elf-as: unrecognized option '-idirafter'


For a full log:

http://law-sandy.freeddns.org:8080/job/fr30-elf/1984/console

Hopefully this is easy to fix so we can get those ports under regular 
testing again.

Jeff