feat: Runtime enum (#1208)

* fix: Fix no_std, avoid future issues

* Gate feature-specific imports

* Make `cubecl-core` no_std

* use core::sync::atomic instead of portable_atomic

* Enable std for tests by default

* Proper fix for exported tests

* Use normal `Option` for `CubeOption`

* Implement if let

* Implement more `Options` methods

* Fix `unwrap_or_default`

* Fix clippy

* Fix `is_none`

* Fix `as_ref` name

* WIP

* Add `IntoRuntime` derive

* Implement `Assign`

* Implement `Branch::Unreachable`

* Add wildcard support

* Move match detection into parse file

* Fixes and workarounds

* Implement runtime `Option`

* Fixes

* Implement runtime if let

* Implement `derive_expand`

* Use signed discriminant, clean up runtime option

* Require `ScalarArgSettings` for `Numeric`

* Fix `trailing_zeros` on Vulkan

* Fix liveness analysis ordering

* Add runtime enums to book

* Fixes

* Ignore tests on unstable option methods

* Fix `ExpandElementAssign`

* Fixes

* Format

* Normalize usize ranges

* Fix clippy and u64 indexing on Vulkan

* Fix read on dummy server

Author: wingertge

crates/cubecl-common/src/device/handle/tests_recursive.rs

@@ -1,5 +1,6 @@
 #[test]
 #[should_panic]
+#[allow(clippy::all)]
 fn test_recursive_execution_same_state() {
     let device_id = DeviceId {
         type_id: 10,

crates/cubecl-core/src/frontend/barrier.rs

@@ -38,8 +38,8 @@ impl CubePrimitive for Barrier {
     }
 }
 
-impl ExpandElementIntoMut for Barrier {
-    fn elem_into_mut(_scope: &mut Scope, elem: ExpandElement) -> ExpandElement {
+impl ExpandElementAssign for Barrier {
+    fn elem_init_mut(_scope: &mut Scope, elem: ExpandElement) -> ExpandElement {
         elem
     }
 }
@@ -48,8 +48,8 @@ impl CubeType for BarrierToken {
     type ExpandType = ExpandElementTyped<BarrierToken>;
 }
 
-impl ExpandElementIntoMut for BarrierToken {
-    fn elem_into_mut(_scope: &mut crate::ir::Scope, elem: ExpandElement) -> ExpandElement {
+impl ExpandElementAssign for BarrierToken {
+    fn elem_init_mut(_scope: &mut crate::ir::Scope, elem: ExpandElement) -> ExpandElement {
         elem
     }
 }