Update to 8.2.0

Changelog:
General Improvements

    Fixed LTO link-time performance problems caused by an overflow in the
    partitioning algorithm while building large binaries.

Language Specific Changes
C++
GCC 8.2 fixed a bug introduced in GCC 8.1 affecting passing or returning of
classes with a deleted copy constructor and defaulted trivial move constructor
(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.
See C++ changes for more details.

Target Specific Changes
IA-32/x86-64

    -mtune=native performance regression PR84413 on Intel Skylake processors
    has been fixed.

(ryoon)