Function projection1_source_real_fast 

pub fn projection1_source_real_fast(
    core_types: &str,
    _interpreter: &str,
    program: &str,
) -> Result<String, String>

In-process variant of projection1_source_real.

Identical in every respect except that the combined PE source is executed by the tree-walking interpreter via interpret_program rather than compiled to Rust and run through cargo (run_logos_source). This makes the genuine LOGOS partial evaluator cheap enough to drive a generative/differential test corpus.