> The implementation of `GetTime` is confusing:
>
> * The value returned by `GetTime` is assumed to be equal to `GetTime<std::chrono::seconds>()`. Both are mockable and the only difference is return type, the value itself is equal. However, the implementation does not support this assumption.
>
> * On some systems, `time_t` might be a signed 32-bit integer (https://en.cppreference.com/w/c/chrono/time), thus breaking in the year 2038, whereas `GetTime<std::chrono::seconds>` does not. Also, `time_t` might be `-1` "on error", where "error" is unspecified.
>
> * `GetTime<std::chrono::seconds>` calls `GetTimeMicros`, which calls `GetSystemTime`, which calls `std::chrono::system_clock::now`, which doesn't have the above issues. See https://en.cppreference.com/w/cpp/chrono/system_clock/now
>
> * `GetTimeMicros` and the internal-only `GetSystemTime` will likely be renamed (to clarify they are the non-mockable non-monotonic system time) or removed in the future to be replaced by appropriate `std::chrono::time_point<Clock>` getters.
>
>
> Fix all issues by:
>
> * making `GetTime()` an alias for `GetTime<std::chrono::seconds>().count()`.
>
> * inlining the needed parts of `GetSystemTime` directly instead of needlessly increasing the function call stack with functions that are likely to be removed in the future.
This is a backport of core#24871
Depends on D11790