Multiplication/arithmetic operators with matrices are not inferred correctly

[GoNZooo]

When we multiply matrices with things we lose inference:

m1, m2: matrix[4, 4]f32
v1, v2: [4]f32
v3 := v1 * v2 // v3: [4]f32
v4 := 6 * v1 // v4: [4]f32
v5 := v1 * m1 // v5: UNKNOWN
v6 := m1 * v1 // v6: UNKNOWN
m3 := m1 * m2 // m3: <undefined>
m4 := 2 * m1 // m4: `UNKNOWN`

Vector values seem to generally keep type information, but when a matrix type is involved in a multiplication (I would expect most arithmetic) type inference is lost.