Update to the GCC 8.2 release, the second in the GCC 8 series.

This fixes more than 99 bugs, among others a performance regression
with -mtune=native on Intel Skylake chips has been fixed.

This also fixes a bug introduced in GCC 8.1 affecting passing or
returning of classes with a deleted copy constructor and defaulted
trivial move constructor (GCC bug c++/86094). GCC 8.2 introduces
-fabi-version=13 and makes it the default; ABI incompatibilities
between GCC 8.1 and 8.2 can be reported with -Wabi=12.