Irix6 long doubles implemented wrong? (27_io/ostream_inserter_arith)

[David Edelsohn]

	The IBM long double implementation on AIX uses helper functions
for addition, subtraction, multiplication, and division.  I expect those
functions will be contributed in the near future.

	The functions are written in Fortran and utilize complex double
precision floating point arguments and return values.  Until the GCC FP
complex parameter passing is fixed, the implementation cannot be used.

David