[PATCH] fix compile error with clang

[Dave Murphy]

Updated changelog per advice from simark on IRC

2018-12-20  Dave Murphy  <davem@devkitpro.org>

    * dtrace-probe.c (dtrace_static_probe_ops): Explicit zero initialise.
    * probe.c (any_static_probe_ops): Ditto.
    * record-btrace.c (record_btrace_thread_observer_token): Ditto.
    * stap-probe.c (stap_static_probe_ops): Ditto.
    * tui/tui-hooks.c (tui_observers_token): Ditto.
    * unittests/observable-selftests.c (token1, token2, token3): Ditto.

On Thu, Dec 20, 2018 at 5:25 PM Dave Murphy <davem@devkitpro.org> wrote:
>
> Cross compiling for macOS using osxcross gives errors of the form
> "error: default initialization of an object of ... without a
> user-provided default constructor"
>
> Fixed by attached patch, tested compile with mingw-w64, osxcross and
> linux native builds.
>
> 2018-12-20  Dave Murphy  <davem@devkitpro.org>
>
>     * gdb/dtrace-probe.c (dtrace_static_probe_ops): explicit zero initialise.
>     * gdb/probe.c (any_static_probe_ops): ditto
>     * gdb/record-btrace.c (record_btrace_thread_observer_token): ditto
>     * gdb/stap-probe.c (stap_static_probe_ops): ditto
>     * gdb/tui/tui-hooks.c (tui_observers_token): ditto
>     * gdb/unittests/observable-selftests.c (token1, token2, token3): ditto