* lib/fenv.in.h (fegetround, fesetround): New declarations.
* lib/fenv-private.h: New file, based on glibc.
* lib/fenv-round.c: New file, based on glibc.
* m4/mathfunc.m4 (gl_MATHFUNC): Handle also the type fp_rnd.
* m4/fenv-rounding.m4: New file.
* modules/fenv (Depends-on): Add snippet/c++defs.
(Makefile.am): Substitute $(CXXDEFS_H) into fenv.h.
* modules/fenv-rounding: New file.
* doc/posix-functions/fegetround.texi: Mention the new module.
* doc/posix-functions/fesetround.texi: Likewise.