[Bug go/78144] New: FAIL: time on systems with tzdata2016g installed

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78144

            Bug ID: 78144
           Summary: FAIL: time on systems with tzdata2016g installed
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: ubizjak at gmail dot com
                CC: cmang at google dot com
  Target Milestone: ---

The "time" testcase fails on systems with tzdata2016g installed. tzdata2016g
ChangLog says:

  Changes to past and future time zone abbreviations

    The Factory zone now uses the time zone abbreviation -00 instead
    of a long English-language string, as -00 is now the normal way to
    represent an undefined time zone.

    Several zones in Antarctica and the former Soviet Union, along
    with zones intended for ships at sea that cannot use POSIX TZ
    strings, now use numeric time zone abbreviations instead of
    invented or obsolete alphanumeric abbreviations.  The affected
    zones are Antarctica/Casey, Antarctica/Davis,
    Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
    Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
    Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
    Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
    Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
    Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
    Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
    Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
    Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
    Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
    Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
    Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
    Europe/Minsk, Europe/Samara, Europe/Volgograd, and
    Indian/Kerguelen.  For Europe/Moscow the invented abbreviation MSM
    was replaced by +05, whereas MSK and MSD were kept as they are not
    our invention and are widely used.

The name of Etc/GMT+1 timezone, which is used in the test, is now changed to
"-01", as evident from:

$ TZ=Etc/GMT+1 date +%Z
-01

Proposed patch that fixes the failure is at [1].

[1] https://gcc.gnu.org/ml/gcc-patches/2016-10/msg01404.html