This MR fixes several issues with the integration pipeline.
Fixes an oversight introduced in !344 (merged). The issue was with expressions like:
a: scalar float = CastFunc(b: vector float, float)The mentioned MR used get_type_of_expression to determine whether an expression will be vectorized.
That works in most cases due to type collation but fails for CastFuncs, which are always vectorized.
This MR replaces get_type_of_expression by a small helper function that checks whether an expression is entirely scalar or requires additional vector casts.