Some intrinsics have different rules for the allowed data types than
expressions:
- Vectors and matrices at the same time are not allowed, regardless of
their dimensions. Even if they have the same number of components.
- Any combination of matrices is always allowed, even those when no
matrix fits inside another, e.g.:
float2x3 is compatible with float3x2, resulting in float 2x2.
The common data type is the min on each dimension.
This is the case for max, pow, ldexp, clamp and smoothstep; which suggest that
it is the case for all intrinsics where the operation is applied element-wise.
Tests for mul() are also added as a counter-example where the operation
is not element-wise.
