Auto merge of #132460 - lcnr:questionable-uwu, r=compiler-errors

Use `TypingMode` throughout the compiler instead of `ParamEnv`

Hopefully the biggest single PR as part of https://github.com/rust-lang/types-team/issues/128.

## `infcx.typing_env` while defining opaque types

I don't know how'll be able to correctly handle opaque types when using something taking a `TypingEnv` while defining opaque types. To correctly handle the opaques we need to be able to pass in the current `opaque_type_storage` and return constraints, i.e. we need to use a proper canonical query. We should migrate all the queries used during HIR typeck and borrowck where this matters to proper canonical queries. This is

## `layout_of` and `Reveal::All`

We convert the `ParamEnv` to `Reveal::All` right at the start of the `layout_of` query, so I've changed callers of `layout_of` to already use a post analysis `TypingEnv` when encountering it.

https://github.com/rust-lang/rust/blob/ca87b535a05097df6abbe2a031b057de2cefac5b/compiler/rustc_ty_utils/src/layout.rs#L51

## `Ty::is_[unpin|sized|whatever]`

I haven't migrated `fn is_item_raw` to use `TypingEnv`, will do so in a followup PR, this should significantly reduce the amount of `typing_env.param_env`. At some point there will probably be zero such uses as using the type system while ignoring the `typing_mode` is incorrect.

## `MirPhase` and phase-transitions

When inside of a MIR-body, we can mostly use its `MirPhase` to figure out the right `typing_mode`. This does not work during phase transitions, most notably when transitioning from `Analysis` to `Runtime`:

https://github.com/rust-lang/rust/blob/dae7ac133b9eda152784c075facb31a6688c92b1/compiler/rustc_mir_transform/src/lib.rs#L606-L625

All these passes still run with `MirPhase::Analysis`, but we should only use `Reveal::All` once we're run the `RevealAll` pass. This required me to manually construct the right `TypingEnv` in all these passes. Given that it feels somewhat easy to accidentally miss this going forward, I would maybe like to change `Body::phase` to an `Option` and replace it at the start of phase transitions. This then makes it clear that the MIR is currently in a weird state.

r? `@ghost`

1 files changed, 8 insertions, 10 deletions

diff --git a/compiler/rustc_codegen_cranelift/src/value_and_place.rs b/compiler/rustc_codegen_cranelift/src/value_and_place.rs
index 900d7e69714..6676e684ca0 100644
--- a/compiler/rustc_codegen_cranelift/src/value_and_place.rs
+++ b/compiler/rustc_codegen_cranelift/src/value_and_place.rs
@@ -4,6 +4,7 @@ use cranelift_codegen::entity::EntityRef;
 use cranelift_codegen::ir::immediates::Offset32;
 use cranelift_frontend::Variable;
 use rustc_middle::ty::FnSig;
+use rustc_middle::ty::layout::HasTypingEnv;
 
 use crate::prelude::*;
 
@@ -884,19 +885,17 @@ pub(crate) fn assert_assignable<'tcx>(
             assert_assignable(fx, *a, *b, limit - 1);
         }
         (ty::FnPtr(..), ty::FnPtr(..)) => {
-            let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
-                ParamEnv::reveal_all(),
-                from_ty.fn_sig(fx.tcx),
-            );
+            let from_sig = fx
+                .tcx
+                .normalize_erasing_late_bound_regions(fx.typing_env(), from_ty.fn_sig(fx.tcx));
             let FnSig {
                 inputs_and_output: types_from,
                 c_variadic: c_variadic_from,
                 safety: unsafety_from,
                 abi: abi_from,
             } = from_sig;
-            let to_sig = fx
-                .tcx
-                .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to_ty.fn_sig(fx.tcx));
+            let to_sig =
+                fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), to_ty.fn_sig(fx.tcx));
             let FnSig {
                 inputs_and_output: types_to,
                 c_variadic: c_variadic_to,
@@ -932,9 +931,8 @@ pub(crate) fn assert_assignable<'tcx>(
         (&ty::Dynamic(from_traits, _, _from_kind), &ty::Dynamic(to_traits, _, _to_kind)) => {
             // FIXME(dyn-star): Do the right thing with DynKinds
             for (from, to) in from_traits.iter().zip(to_traits) {
-                let from =
-                    fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from);
-                let to = fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to);
+                let from = fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), from);
+                let to = fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), to);
                 assert_eq!(
                     from, to,
                     "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",