archive: Move JIT/Cranelift to archive during Phase 15 focus

Phase 15 requires concentrated development on PyVM and LLVM backends only.
JIT/Cranelift was causing build confusion and distracting AI developers.

## Archived Components
- src/jit/ → archive/jit-cranelift/src/jit/
- src/backend/cranelift/ → archive/jit-cranelift/src/backend/cranelift/
- JIT Box modules → archive/jit-cranelift/src/boxes/
- JIT scripts → archive/jit-cranelift/scripts/, tools/
- clif_adapter.rs → archive/jit-cranelift/src/semantics/

## Build Changes
- Cargo.toml: Comment out cranelift-jit feature and dependencies
- src/lib.rs: Disable JIT module declaration
- src/boxes/mod.rs: Disable JIT Box module declarations
- src/semantics/mod.rs: Disable clif_adapter module
- debug_box.rs: Replace JIT calls with archive stubs

## Documentation
- archive/jit-cranelift/ARCHIVE_NOTES.md: Complete restoration guide
- Reason: Phase 15 selfhosting focus (80k→20k line reduction)
- Restoration: Full procedure documented for future revival

This eliminates build errors and AI developer confusion, enabling
focused Phase 15 development on PyVM/LLVM backends only.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/semantics/clif_adapter.rs

@@ -1,124 +0,0 @@
-use super::Semantics;
-use crate::jit::lower::builder::{BinOpKind, CmpKind, IRBuilder};
-use crate::mir::{BasicBlockId, ValueId};
-
-/// Adapter that translates Semantics operations into IRBuilder calls (Cranelift path)
-pub struct ClifSemanticsAdapter<'a> {
-    pub builder: &'a mut dyn IRBuilder,
-}
-
-impl<'a> ClifSemanticsAdapter<'a> {
-    pub fn new(builder: &'a mut dyn IRBuilder) -> Self {
-        Self { builder }
-    }
-}
-
-impl<'a> Semantics for ClifSemanticsAdapter<'a> {
-    type Val = ();
-    type Ptr = ValueId;
-    type BB = BasicBlockId;
-
-    fn const_i64(&mut self, v: i64) -> Self::Val {
-        self.builder.emit_const_i64(v);
-    }
-    fn const_f64(&mut self, v: f64) -> Self::Val {
-        self.builder.emit_const_f64(v);
-    }
-    fn const_bool(&mut self, v: bool) -> Self::Val {
-        self.builder.emit_const_i64(if v { 1 } else { 0 });
-    }
-    fn const_null(&mut self) -> Self::Val {
-        self.builder.emit_const_i64(0);
-    }
-    fn const_str(&mut self, _s: &str) -> Self::Val {
-        self.builder.emit_const_i64(0);
-    }
-
-    fn neg(&mut self, _x: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Sub);
-    }
-    fn not(&mut self, _x: Self::Val) -> Self::Val { /* handled via compare/select in LowerCore */
-    }
-    fn bit_not(&mut self, _x: Self::Val) -> Self::Val { /* not used here */
-    }
-    fn add(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Add);
-    }
-    fn sub(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Sub);
-    }
-    fn mul(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Mul);
-    }
-    fn div(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Div);
-    }
-    fn modulo(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_binop(BinOpKind::Mod);
-    }
-    fn cmp_eq(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Eq);
-    }
-    fn cmp_ne(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Ne);
-    }
-    fn cmp_lt(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Lt);
-    }
-    fn cmp_le(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Le);
-    }
-    fn cmp_gt(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Gt);
-    }
-    fn cmp_ge(&mut self, _a: Self::Val, _b: Self::Val) -> Self::Val {
-        self.builder.emit_compare(CmpKind::Ge);
-    }
-
-    fn alloca_ptr(&mut self, _vid: ValueId) -> Self::Ptr {
-        _vid
-    }
-    fn load(&mut self, _ptr: &Self::Ptr) -> Self::Val {
-        self.builder.load_local_i64(_ptr.as_u32() as usize);
-    }
-    fn store(&mut self, _ptr: &Self::Ptr, _v: Self::Val) {
-        self.builder.store_local_i64(_ptr.as_u32() as usize);
-    }
-    fn jump(&mut self, _target: BasicBlockId) { /* handled by LowerCore */
-    }
-    fn branch(&mut self, _cond: Self::Val, _then_bb: BasicBlockId, _else_bb: BasicBlockId) {
-        /* handled by LowerCore */
-    }
-    fn phi_select(&mut self, _incoming: &[(BasicBlockId, Self::Val)]) -> Self::Val {
-        ()
-    }
-    fn ret(&mut self, _v: Option<Self::Val>) {
-        self.builder.emit_return();
-    }
-
-    fn new_box(&mut self, _type_id: i64, _args: &[Self::Val]) -> Self::Val {
-        ()
-    }
-    fn box_call_tagged(
-        &mut self,
-        _type_id: i64,
-        _method_id: i64,
-        _recv: Self::Val,
-        _argv: &[Self::Val],
-        _tags: &[i64],
-    ) -> Self::Val {
-        ()
-    }
-    fn extern_call(&mut self, _iface: &str, _method: &str, _args: &[Self::Val]) -> Self::Val {
-        ()
-    }
-
-    fn barrier_read(&mut self, v: Self::Val) -> Self::Val {
-        v
-    }
-    fn barrier_write(&mut self, _ptr: &Self::Ptr, v: Self::Val) -> Self::Val {
-        v
-    }
-    fn safepoint(&mut self) { /* Lowered via explicit hostcall in LowerCore path */
-    }
-}

src/semantics/mod.rs

@@ -84,5 +84,5 @@ pub trait SemanticsExt: Semantics {
 
 impl<T: Semantics> SemanticsExt for T {}
 
-pub mod clif_adapter;
+// pub mod clif_adapter; // ARCHIVED: moved to archive/jit-cranelift/
 pub mod vm_impl;