Function jit_load_col_bool 

pub extern "C" fn jit_load_col_bool(
    ctx: *mut JITContext,
    col_id: u32,
    row_ref: u64,
) -> u64

Load a boolean value from a column (stored as f64: 0.0=false, else true).

Returns TAG_BOOL_TRUE or TAG_BOOL_FALSE.