Rollup merge of #126552 - fee1-dead-contrib:rmfx, r=compiler-errors

Remove use of const traits (and `feature(effects)`) from stdlib

The current uses are already unsound because they are using non-const impls in const contexts. We can reintroduce them by reverting the commit in this PR, after #120639 lands.

Also, make `effects` an incomplete feature.

cc `@rust-lang/project-const-traits`
r? `@compiler-errors`

Author: matthiaskrgr

compiler/rustc_feature/src/unstable.rs

@@ -449,7 +449,7 @@ declare_features! (
     /// Allows `dyn* Trait` objects.
     (incomplete, dyn_star, "1.65.0", Some(102425)),
     /// Uses generic effect parameters for ~const bounds
-    (unstable, effects, "1.72.0", Some(102090)),
+    (incomplete, effects, "1.72.0", Some(102090)),
     /// Allows exhaustive pattern matching on types that contain uninhabited types.
     (unstable, exhaustive_patterns, "1.13.0", Some(51085)),
     /// Allows explicit tail calls via `become` expression.

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -429,17 +429,17 @@ pub fn check_intrinsic_type(
 
             sym::ptr_guaranteed_cmp => (
                 1,
-                1,
+                0,
                 vec![Ty::new_imm_ptr(tcx, param(0)), Ty::new_imm_ptr(tcx, param(0))],
                 tcx.types.u8,
             ),
 
             sym::const_allocate => {
-                (0, 1, vec![tcx.types.usize, tcx.types.usize], Ty::new_mut_ptr(tcx, tcx.types.u8))
+                (0, 0, vec![tcx.types.usize, tcx.types.usize], Ty::new_mut_ptr(tcx, tcx.types.u8))
             }
             sym::const_deallocate => (
                 0,
-                1,
+                0,
                 vec![Ty::new_mut_ptr(tcx, tcx.types.u8), tcx.types.usize, tcx.types.usize],
                 tcx.types.unit,
             ),
@@ -478,16 +478,16 @@ pub fn check_intrinsic_type(
             | sym::frem_algebraic => (1, 0, vec![param(0), param(0)], param(0)),
             sym::float_to_int_unchecked => (2, 0, vec![param(0)], param(1)),
 
-            sym::assume => (0, 1, vec![tcx.types.bool], tcx.types.unit),
-            sym::likely => (0, 1, vec![tcx.types.bool], tcx.types.bool),
-            sym::unlikely => (0, 1, vec![tcx.types.bool], tcx.types.bool),
+            sym::assume => (0, 0, vec![tcx.types.bool], tcx.types.unit),
+            sym::likely => (0, 0, vec![tcx.types.bool], tcx.types.bool),
+            sym::unlikely => (0, 0, vec![tcx.types.bool], tcx.types.bool),
 
             sym::read_via_copy => (1, 0, vec![Ty::new_imm_ptr(tcx, param(0))], param(0)),
             sym::write_via_move => {
                 (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], tcx.types.unit)
             }
 
-            sym::typed_swap => (1, 1, vec![Ty::new_mut_ptr(tcx, param(0)); 2], tcx.types.unit),
+            sym::typed_swap => (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)); 2], tcx.types.unit),
 
             sym::discriminant_value => {
                 let assoc_items = tcx.associated_item_def_ids(
@@ -566,20 +566,20 @@ pub fn check_intrinsic_type(
 
             sym::black_box => (1, 0, vec![param(0)], param(0)),
 
-            sym::is_val_statically_known => (1, 1, vec![param(0)], tcx.types.bool),
+            sym::is_val_statically_known => (1, 0, vec![param(0)], tcx.types.bool),
 
-            sym::const_eval_select => (4, 1, vec![param(0), param(1), param(2)], param(3)),
+            sym::const_eval_select => (4, 0, vec![param(0), param(1), param(2)], param(3)),
 
             sym::vtable_size | sym::vtable_align => {
                 (0, 0, vec![Ty::new_imm_ptr(tcx, tcx.types.unit)], tcx.types.usize)
             }
 
             // This type check is not particularly useful, but the `where` bounds
             // on the definition in `core` do the heavy lifting for checking it.
-            sym::aggregate_raw_ptr => (3, 1, vec![param(1), param(2)], param(0)),
-            sym::ptr_metadata => (2, 1, vec![Ty::new_imm_ptr(tcx, param(0))], param(1)),
+            sym::aggregate_raw_ptr => (3, 0, vec![param(1), param(2)], param(0)),
+            sym::ptr_metadata => (2, 0, vec![Ty::new_imm_ptr(tcx, param(0))], param(1)),
 
-            sym::ub_checks => (0, 1, Vec::new(), tcx.types.bool),
+            sym::ub_checks => (0, 0, Vec::new(), tcx.types.bool),
 
             sym::simd_eq
             | sym::simd_ne