GDB 9.1 release -- 2020-01-02 update

[Joel Brobecker <brobecker@adacore.com>]

Hi everyone,

Happy New Year! Am I the only one wondering where the End of Year
Holidays went?!?

Quick status update, based on feedback for the branch, so far.

Added since the last update:

  - [Joel/Tom/Simon] Report error if trying to build GDB in tree
    https://www.sourceware.org/ml/gdb/2019-12/msg00034.html

    I think this is an acceptable limitation, but we haven't really
    made the official decision that it is. If we do, then we can
    patch configure to just report a clear error.

    Tom suggested an alternative, which is to revert the gnulib
    move on the branch. From my perspective, this is less desirable,
    because it is a riskier move.

  - [Andrew] unexpected disassembly output in backtrace
    https://sourceware.org/ml/gdb-patches/2019-12/msg01007.html

  - [Christian] Unable to build GDB on recent MinGW due to _FORTIFY_SOURCE
    https://sourceware.org/ml/gdb-patches/2019-12/msg00787.html

    I hestitated a lot on the resolution of this issue, but
    in the end, I am OK with the proposed approach of not
    setting _FORTIFY_SOURCE on MinGW targets.

    I will send a comment on the thread in question.

Still Open:

  - [Eliz] libtcf fails to build on MinGW
    https://sourceware.org/bugzilla/show_bug.cgi?id=25155

    Problem reported to binutils on Dec 17th, but so far
    no answer as far as I can tell.
    https://sourceware.org/ml/binutils/2019-12/msg00277.html

    Joel to send a copy of the patch to binutils, which should
    make it easier for people to review, compared to a reference
    to a bugzilla entry. Plead if necessary ;-).

Fixed since the last update:

  - [EliZ] readline/colors.c build failure

        Caused by S_IXGRP and S_IXOTH not being defined on MinGW.

  - [EliZ] configure warning when checking for pthread-config

Cheers!
-- 
Joel