Log Message:
gdb: update to 8.1.

local changes: use plist var for gcore.
XXX don't install gcore.1 that doesn't appear to be installed but exists
remove merged patches.

GDB 8.1 includes the following changes and enhancements:

  * Breakpoints on C++ functions are now set on all scopes by default
    ("wild" matching);

  * Support for inserting breakpoints on functions marked with C++ ABI tags;

  * Target floating-point arithmetic emulation during expression evaluation
    (requires MPFR 3.1 or later);

  * Various Python Scripting enhancements;

  * Improved Rust support; in particular, Trait objects can now be inspected
    when debugging Rust code;

  * GDB no longer makes assumptions about the type of symbols without
    debugging information to avoid producing erroneous and often confusing
    results;

  * The 'enable' and 'disable' commands now accept a range of breakpoint
    locations;

  * New 'starti' command to start the program at the first instruction;

  * New 'rbreak' command to insert a number of breakpoints via a regular
    expression pattern (requires Python);

  * The 'ptype' command now supports printing the offset and size of
    the fields in a struct;

  * The 'gcore' command now supports dumping all the memory mappings
    ('-a' command-line option);

  * New shortcuts for TUI Single-Key mode: 'i' for stepi, and 'o' for nexti;

  * GDBserver enhancements:
    ** Support for transmitting environment variables to GDBserver;
    ** Support for starting inferior processes with a specified initial
       working directory;
    ** On Unix systems, support for globbing expansion and variable
       substitution of inferior command-line arguments;

  * Various completion enhancements;

  * The command used to compile and inject code with the 'compile' command
    is now configurable;

  * New '--readnever' command-line option to speed the GDB startup when
    debugging information is not needed;

  * Support for the following new native configurations:
    ** FreeBSD/aarch64 (aarch64*-*-freebsd*);
    ** FreeBSD/arm (arm*-*-freebsd*);

  * Support for the following new targets:
    ** FreeBSD/aarch64 (aarch64*-*-freebsd*);
    ** FreeBSD/arm (arm*-*-freebsd*);
    ** OpenRISC ELF (or1k*-*-elf)

  * Removed support for the following targets and native configurations:
    ** Solaris2/x86 (i?86-*-solaris2.[0-9]);
    ** Solaris2/sparc (sparc*-*-solaris2.[0-9]);

For a complete list and more details on each item, please see the gdb/NEWS
file, available at:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob_plain;f=gdb/NEWS;hb=gdb-8.1-release