refactor(ir): use u64 directly instead of spans for instructions

crates/ir/src/id.rs

@@ -6,10 +6,8 @@
 //!
 //! Instead, this module offers an alternative way to refer to specific instances:
 //!
-//! - [`Instruction`]s are referred to as their **byte [`Span`]s** in the source code,
-//!   so effectively where they are written in the source code.
-//!   (Or if coming from [`crate::semi_human::GraphIr`],
-//!   it's just a fictional number floating in space.)
+//! - [`Instruction`]s are effectively just a number floating in space,
+//!   incremented each time a new instruction is referred to.
 //! - [`Socket`]s contain
 //!   - what [`Instruction`] they belong to
 //!   - which index they occupy on it
@@ -19,22 +17,12 @@
 
 use serde::{Deserialize, Serialize};
 
-use crate::Span;
-
-/// One specific instruction, and where it is found in code.
+/// One specific instruction.
 ///
 /// It does **not** contain what kind of instruction this is.
 /// Refer to [`crate::instruction::Kind`] for this instead.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct Instruction(pub(super) Span);
-
-impl Instruction {
-    /// Where this instruction is written down.
-    #[must_use]
-    pub fn span(&self) -> &Span {
-        &self.0
-    }
-}
+pub struct Instruction(pub(super) u64);
 
 /// On an **instruction**, accepts incoming data.
 ///