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, 7 insertions, 3 deletions

diff --git a/src/base.rs b/src/base.rs
index da3818ca25e..1b91d251bfd 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -666,7 +666,7 @@ fn codegen_stmt<'tcx>(
                             let func_ref = fx.get_function_ref(
                                 Instance::resolve_for_fn_ptr(
                                     fx.tcx,
-                                    ParamEnv::reveal_all(),
+                                    ty::TypingEnv::fully_monomorphized(),
                                     def_id,
                                     args,
                                 )
@@ -841,14 +841,18 @@ fn codegen_stmt<'tcx>(
                     lval.write_cvalue(fx, CValue::by_val(operand, box_layout));
                 }
                 Rvalue::NullaryOp(ref null_op, ty) => {
-                    assert!(lval.layout().ty.is_sized(fx.tcx, ParamEnv::reveal_all()));
+                    assert!(lval.layout().ty.is_sized(fx.tcx, ty::ParamEnv::reveal_all()));
                     let layout = fx.layout_of(fx.monomorphize(ty));
                     let val = match null_op {
                         NullOp::SizeOf => layout.size.bytes(),
                         NullOp::AlignOf => layout.align.abi.bytes(),
                         NullOp::OffsetOf(fields) => fx
                             .tcx
-                            .offset_of_subfield(ParamEnv::reveal_all(), layout, fields.iter())
+                            .offset_of_subfield(
+                                ty::TypingEnv::fully_monomorphized(),
+                                layout,
+                                fields.iter(),
+                            )
                             .bytes(),
                         NullOp::UbChecks => {
                             let val = fx.tcx.sess.ub_checks();