Move state transform after optimizations.

Author: cjgillot

compiler/rustc_mir_transform/src/coroutine/mod.rs

@@ -160,6 +160,7 @@ const SELF_ARG: Local = Local::arg(0);
 pub(crate) const CTX_ARG: Local = Local::arg(1);
 
 /// A `yield` point in the coroutine.
+#[derive(Debug)]
 struct SuspensionPoint<'tcx> {
     /// State discriminant used when suspending or resuming at this point.
     state: usize,

compiler/rustc_mir_transform/src/lib.rs

@@ -647,7 +647,6 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         &add_moves_for_packed_drops::AddMovesForPackedDrops,
         &erase_deref_temps::EraseDerefTemps,
         &elaborate_box_derefs::ElaborateBoxDerefs,
-        &coroutine::StateTransform,
         &Lint(known_panics_lint::KnownPanicsLint),
     ];
     pm::run_passes_no_validate(tcx, body, passes, Some(MirPhase::Runtime(RuntimePhase::Initial)));
@@ -765,6 +764,7 @@ pub(crate) fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'
             &simplify::SimplifyLocals::Final,
             &multiple_return_terminators::MultipleReturnTerminators,
             &large_enums::EnumSizeOpt { discrepancy: 128 },
+            &coroutine::StateTransform,
             // Some cleanup necessary at least for LLVM and potentially other codegen backends.
             &add_call_guards::CriticalCallEdges,
             // Cleanup for human readability, off by default.

compiler/rustc_mir_transform/src/shim.rs

@@ -115,7 +115,6 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceKind<'tcx>) -> Body<
                     tcx,
                     &mut body,
                     &[
-                        &mentioned_items::MentionedItems,
                         &abort_unwinding_calls::AbortUnwindingCalls,
                         &add_call_guards::CriticalCallEdges,
                     ],

compiler/rustc_mir_transform/src/shim/async_destructor_ctor.rs

@@ -207,6 +207,7 @@ fn build_adrop_for_coroutine_shim<'tcx>(
     body.source.instance = instance;
     body.phase = MirPhase::Runtime(RuntimePhase::Initial);
     body.var_debug_info.clear();
+    body.mentioned_items = None;
 
     // converting `(_1: Pin<&mut CorLayout>, _2: &mut Context<'_>) -> Poll<()>`
     // into `(_1: Pin<&mut ProxyLayout>, _2: &mut Context<'_>) -> Poll<()>`