Output assignments with direct access in function calls generate incorrect code

[volsa]

Is your feature request related to a problem? Please describe.
Output assignment with direct access in function calls, e.g. fun(foo => bar.3), currently do not modify the right side (i.e. bar.3) with the outputs result. Specifically the way we generate IR for output assignments in function calls works by

1. Loading bar
2. Generating the expression for bar.3 using some shifting magic and boolean operators
3. Storing the result of the generated expression into a temporary variable
4. Calling the function, passing the temporary variable as a pointer

However, a 5th step is missing in which we store the temporary variable back into bar. See

define i32 @main() section "fn-main:i32" {
entry:
  ; [...]

  ; Code for `fun(foo => bar.4)`
  %load_bar1 = load i32, i32* %bar, align 4
  %shift = ashr i32 %load_bar1, 4
  %1 = trunc i32 %shift to i8
  %2 = and i8 %1, 1
  %load_bar2 = load i32, i32* %bar, align 4
  %shift3 = ashr i32 %load_bar2, 4
  %3 = trunc i32 %shift3 to i8
  %4 = and i8 %3, 1
  %5 = alloca i8, align 1
  store i8 %4, i8* %5, align 1
  call void @fun(i8* %5) 
  ; Missing store call for `bar` variable

  ; [...]
}

FUNCTION fun
    VAR_OUTPUT
        foo : BOOL;
    END_VAR

    foo := TRUE;
END_FUNCTION

FUNCTION_BLOCK fb
    VAR_OUTPUT
        foo : BOOL;
    END_VAR

    foo := TRUE;
END_FUNCTION_BLOCK


FUNCTION main : DINT
    VAR
        bar : DINT;
        myFb : fb;
    END_VAR

    bar := 0;
    printf('%d$N', bar);
    fun(foo => bar.4);  // ..._0001_0000
    printf('%d$N', bar);

    bar := 0;
    printf('%d$N', bar);
    myFb(foo => bar.4);  // ..._0001_0000
    printf('%d$N', bar);
END_FUNCTION