Fixmes and style fixes

Author: oli-obk

src/librustc_mir/interpret/eval_context.rs

@@ -641,6 +641,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpretCx<'mir, 'tcx, M> {
         &self,
         gid: GlobalId<'tcx>,
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::PointerTag>> {
+        // FIXME(oli-obk): make this check an assertion that it's not a static here
+        // FIXME(RalfJ, oli-obk): document that `Place::Static` can never be anything but a static
+        // and `ConstValue::Unevaluated` can never be a static
         let param_env = if self.tcx.is_static(gid.instance.def_id()) {
             ty::ParamEnv::reveal_all()
         } else {

src/librustc_mir/interpret/validity.rs

@@ -396,6 +396,7 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
                 if let Some(ref mut ref_tracking) = self.ref_tracking {
                     assert!(self.const_mode, "We should only do recursie checking in const mode");
                     let place = self.ecx.ref_to_mplace(value)?;
+                    // FIXME(RalfJ): check ZST for inbound pointers
                     if size != Size::ZERO {
                         // Non-ZST also have to be dereferencable
                         let ptr = try_validation!(place.ptr.to_ptr(),

src/librustc_mir/interpret/visitor.rs

@@ -81,6 +81,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Value<'mir, 'tcx, M> for OpTy<'tcx, M::
         ecx.operand_field(self, field)
     }
 }
+
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Value<'mir, 'tcx, M> for MPlaceTy<'tcx, M::PointerTag> {
     #[inline(always)]
     fn layout(&self) -> TyLayout<'tcx> {