Add new port math/opensolaris-libm

In 2006, Sun Microsystems released math and vector math libraries as

part of their effort to open-source Solaris:

libmvec - vector math library

This library contains function to evaluate common mathematical functions for several arguments at once. The argument values are specified by one or more vectors (arrays) of data, and the corresponding result values are stored in another vector.

libm - C99 math library

Functions in this library provide common elementary mathematical functions and floating point environment routines defined by System V, ANSI C, POSIX, and so on. Additional functions in this library provide extended support for handling floating point exceptions.

The original source has been modified to build on FreeBSD and DragonFly

using GCC or clang and the GNU assembler. All fixes introduced by Nexenta

and Illumos projects have also been incorporated. Missing x86_64 variants

of lrint and lround have added. The floating-point exception logging

including address->symbol tranlation has also been implemented.