[wgsl-in] Type aliases for a vecN<T> doesn't work when constructing vec from a single argument

[Wumpf]

Given
type Vec3 = vec3<f32>;

Try to create a Vec3 from a single argument:
let thing = Vec3(0.5);

I get an "Expression is invalid" error.

In contrast these things all work fine:

    let a = Vec3(0.0, 0.0, 0.0);
    let c = vec3<f32>(0.0);
    let b = Vec3(vec2<f32>(0.0), 0.0);
    let d = Vec3(vec2<f32>(0.0), 0.0);