4213 – Strange behaviour with static void[] arrays

This code always worked:
struct X {
 union {
 void[] a;
 void[9] b;
 }
}
However, if you remove the union (so that a, b are direct struct members), it stops working and outputs "Error: integral constant must be scalar type, not void" (without line number information!). It also stops compiling if you remove the "a" member.
It also generates a wrong .sizeof for the struct (12 instead of 9*4). Not sure what exactly is going on.

Never mind that bit about the struct's size, b is 9 bytes, aligned on 4 = 12 bytes. Correct.

Note that this compiles on v2.046, but it stops compiling if you remove the =void, so that problem can be by design:
void main() {
 void[1] a = void;
}

improved error message with changeset 496