Input variables of structs should be passed as (const) pointer

[Angus-Bethke-Bachmann]

Describe the bug
Input variables of structs should be passed as (const) pointer.

To Reproduce
I have the following struct defined in plc:

TYPE
    TIME_SYSTIMEDATE : STRUCT
        Sec    : DINT;        (**< Seconds after the minute [0..60], leap second allowed *)
        Min    : DINT;        (**< Minutes after the hour [0..59] *)
        Hour   : DINT;        (**< Hours since midnight [0..23] *)
        Day    : DINT;        (**< Day of the month [1..31] *)
        Month  : DINT;        (**< Months since January [0..11] *)
        Year   : DINT;        (**< Absolute year (e.g. 2025) *)
        Wday   : DINT;        (**< Days since Sunday [0..6], 0 = Sunday *)
        Yday   : DINT;        (**< Days since January 1 [0..365], 0 = Jan 1 *)
        Isdst  : DINT;        (**< -1 = unknown, 0 = off, 1 = on *)
        Gmtoff : DINT;        (**< Seconds east of UTC *)
        Zone   : STRING[64];  (**< Timezone name/abbreviation (NUL-terminated) *)
    END_STRUCT;
END_TYPE

which is then correctly generated in to a c struct definition typedef struct { ... } TIME_SysTimeDate;

When using it as VAR_INPUT I would hope it to get passed as a pointer in C (const would also be nice). In that case the struct does not need to be copied, which in the TIME_SYSTIMEDATE case would be a lot of data.

Expected behavior
When handed to a function, I expect my struct to be passed as a const pointer:

void someFunction(const TIME_SysTimeDate* sysTimeVar)
{
    // Implementation here...
}

Additional context
Orignally reported by Guillaume.