Function compile_or_library_str 

pub fn compile_or_library_str(
    name: &str,
    src: &str,
) -> (Option<Placed>, Diagnostics, SourceMap)

The same, admitting a library: a module with no merge point comes back as a split::Placed whose roles are placeholders rather than as None.

Separate from compile_str rather than replacing it, because “this compiled” and “this is an application” are different questions and every existing caller is asking the second. beck test asks the first (docs/27 §27.4); so does anything that only wants the module’s definitions.