double rounding in x86

[Samuel A. Figueroa]

The "official" C compiler for NEXTSTEP (NeXT's version of Unix) is gcc, and
they have enhanced their version of gcc with a compile-time switch to set
the precision mode on the x86 to double precision.  A lot of NeXT's enhance-
ments to gcc haven't made it into the official FSF source code.  Some of these
enhancements will hopefully be integrated into the official FSF source code
sometime in the not-too-distant future.

- Sam Figueroa (figueroaacs.nyu.edu)