[D1] assert failure expression.c

[bearophile]

> You (or me or someone else) may add this to Bugzilla:
> 
> char[2] foo() {
>     char[2] code;
>     code[1] = "";
>     return code;
> }
> struct Bar {
>     int i = mixin(foo());
> }
> void main() {}

Further reduced:


void foo() {
    char[0] code;
    code[0] = "";
}
struct Bar {
    int i = mixin(foo());
}
void main() {}