gdb: bump to 8.2

gdb: bump to 8.2

*** Changes in GDB 8.2

 Support for the following target has been added:

    RiscV ELF (riscv*-*-elf)

 Support for following targets and native configurations has been removed:

    m88k running OpenBSD (m88*-*-openbsd*)
    SH-5/SH64 ELF (sh64-*-elf*)
    SH-5/SH64 (sh*)
    SH-5/SH64 running GNU/Linux (sh*-*-linux*)
    SH-5/SH64 running OpenBSD (sh*-*-openbsd*)

 Various Python API enhancements
 Aarch64/Linux enhancements:

    SVE support.
    Hardware watchpoints improvements for entities stored at unaligned addresses.
        New "c" response to disable the pager for the rest of the current command.
        C expressions can now use _Alignof, and C++ expressions can now use alignof.
        Improved flexibility for loading symbol files.
        The 'info proc' command nows works on running processes on FreeBSD systems as well as core files created on FreeBSD systems.
        A new --enable-codesign=CERT configure option to automatically codesign GDB after build (useful on MacOS X).

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
(backported from 22535240238b6bcc93bdc356856be36a02aec054)