Function decorate_source 

pub fn decorate_source(src: &str, disabled_keywords: &[&str]) -> String

Produce a copy of src with a file-level ## No <keyword> decorator inserted (just before ## Main, where the parser folds it into the program-wide config) for each disabled-optimization keyword. This is what the benchmarks UI shows on the Logos source when a toggle is flipped off; compiling the result applies the same config the toggle represents.