compiler assert failure with ctfe on simd vector type

[Roderick Gibson]

I get a compiler assert failing when trying to compile the follow 
minimal case:

import core.simd;
void main() {
        auto arr = si;
}

const float4 si = [1f, 1f, 1f, 1f];

This compiles fine:

import core.simd;

void main() {
        auto arr = si;
}

float4 si = [1f, 1f, 1f, 1f];

Should I file this or am I doing something dumb here?