* sysdeps/alpha/fpu/bits/mathdef.h: Define ISO C 9X stuff only if
included from math.h and __USE_ISOC9X is defined.
* sysdeps/generic/bits/mathdef.h: Likewise.
* sysdeps/generic/i386/fpu/mathdef.h: Likewise.
* sysdeps/generic/m68k/fpu/mathdef.h: Likewise.
* sysdeps/generic/powerpc/bits/mathdef.h: Likewise.
* sysdeps/generic/sparc/fpu/bits/mathdef.h: Likewise.
1998-11-10 Andreas Jaeger <aj@arthur.rhein-neckar.de>