Draft: Interpreter, Tests, Debug Info, Misc.

Bit of a mess, lots of TODOs, in the process of cleaning up. Will have distinct changes in separate branches in the future.

Interpreter:

• Added interpreter under hercules_test/hercules_interpreter, covering most basic functionality.
• Missing products / sum types, floating point semantics, but framework is there to add them.

Testing:

• Added test of optimization passes via execution w/ interpreter before and after optimization.

Misc / Debug Info:

• Experimented with different ways of propagating debug info / partitions between passes. All passes should report a list of changes they made, not including gravestone updates. Possibly add default mapping if a pass doesn't want to compute its changes. Current system is quite messy still (comments, code, files).

• Moved Function type to function.rs

hercules_ir/src/build.rs

-use std::collections::HashMap;
+use std::{collections::HashMap, marker::PhantomData};
 
 use crate::*;
 
@@ -414,6 +414,7 @@ impl<'a> Builder<'a> {
             return_type,
             nodes: vec![Node::Start],
             num_dynamic_constants,
+            debug_info: None,
         });
         Ok((id, NodeID::new(0)))
     }