WIP: remove repr(C) check for a baseline crater run

Author: RalfJung

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1540,7 +1540,6 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>)
     enum UnsuitedReason {
         NonExhaustive,
         PrivateField,
-        ReprC,
     }
     struct UnsuitedInfo<'tcx> {
         descr: &'static str,
@@ -1576,14 +1575,6 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>)
                         });
                     }
                 }
-                if def.repr().c() {
-                    return ControlFlow::Break(UnsuitedInfo {
-                        descr: def.descr(),
-                        def_id: def.did(),
-                        args,
-                        reason: UnsuitedReason::ReprC,
-                    });
-                }
                 def.all_fields()
                     .map(|field| field.ty(tcx, args))
                     .try_for_each(|t| check_unsuited_1zst(tcx, t))
@@ -1609,7 +1600,6 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>)
                 let note = match unsuited.reason {
                     UnsuitedReason::NonExhaustive => "is marked with `#[non_exhaustive]`",
                     UnsuitedReason::PrivateField => "contains private fields",
-                    UnsuitedReason::ReprC => "is marked with `#[repr(C)]`",
                 };
                 let field_ty = tcx.def_path_str_with_args(unsuited.def_id, unsuited.args);
                 diag.note(format!(