Initial values not generated with array of struct

[volsa]

Describe the bug
When skipping initialization for some struct fields, a codegen error pops up due to said skipped value not being generated. For example

TYPE STRUCT1 : STRUCT
    node    : DINT;
    myArr   : ARRAY[0..1] OF STRUCT2;
END_STRUCT END_TYPE

TYPE STRUCT2 : STRUCT
    x1  : INT;
    x2  : INT;
END_STRUCT END_TYPE

PROGRAM main
    VAR
        var_init1 : ARRAY[0..1] OF STRUCT1 := [
            (node := 0, myArr := [(x1 := 0)])
        ];
    END_VAR
END_PROGRAM

will yield the following error

error: Some initial values were not generated
Codegen Error: Compilation aborted due to previous errors

Similarly this will not work (myArr := [(x1 := 0, x2 := 1), (x1 := 2, x2 := 3)]).
When initializing x2 / node however, it seem to work i.e. (node := 0, myArr := [(x1 := 0, x2 := 0)]).

Additional context
This seems like a regression due to 5dac39d

[mhasel]

looks similar to #932