Added documentation, ready to merge

crates/forge_analyzer/src/interp.rs

@@ -604,6 +604,7 @@ impl<'cx, C: Runner<'cx>> Interp<'cx, C> {
             .insert_var_with_projection(defid_block, varid, projections, value);
     }
 
+    // this function takes in an operand checks for previous values and returns a value optional
     #[inline]
     pub fn add_value_to_definition(&mut self, defid_block: DefId, lval: Variable, rvalue: Rvalue) {
         if let Variable {