This updates adds the GNU Compiler Collection 8 to openSUSE Leap 42.3.

The update also supplies gcc8 compatible libstdc++, libgcc_s1 and other
gcc derived libraries.

Various optimizers have been improved in GCC 8, several of bugs fixed,
quite some new warnings added and the error pin-pointing and
fix-suggestions have been greatly improved.

The GNU Compiler page for GCC 8 contains a summary of all the changes that
have happened:

https://gcc.gnu.org/gcc-8/changes.html

Also changes needed or common pitfalls when porting software are described on:

https://gcc.gnu.org/gcc-8/porting_to.html