add more sensible API for object handles, add drop instruction

crsn_arith/src/parse.rs

@@ -2,7 +2,7 @@ use crsn::asm::data::{Rd, Wr};
 use crsn::asm::error::Error;
 use crsn::asm::instr::Op;
 use crsn::asm::parse::arg_parser::ArgParser;
-use crsn::module::{AsmModule, ParseOpRes};
+use crsn::module::{CrsnExtension, ParseOpRes};
 
 use crate::defs::ArithOp;
 
@@ -12,14 +12,14 @@ pub struct ArithOps {
 }
 
 impl ArithOps {
-    pub fn new() -> Box<dyn AsmModule> {
+    pub fn new() -> Box<dyn CrsnExtension> {
         Box::new(Self {
             _internal: ()
         })
     }
 }
 
-impl AsmModule for ArithOps {
+impl CrsnExtension for ArithOps {
     fn name(&self) -> &'static str {
         "arith"
     }