float and int vars are trivially copy

compiler/rustc_hir_analysis/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs

@@ -198,6 +198,10 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
 
         // If the type being assigned needs dropped, then the mutation counts as a borrow
         // since it is essentially doing `Drop::drop(&mut x); x = new_value;`.
+        //
+        // FIXME(drop-tracking): We need to be more responsible about inference
+        // variables here, since `needs_drop` is a "raw" type query, i.e. it
+        // basically requires types to have been fully resolved.
         if assignee_place.place.base_ty.needs_drop(self.tcx, self.param_env) {
             self.places
                 .borrowed

compiler/rustc_middle/src/ty/sty.rs

@@ -2205,7 +2205,10 @@ impl<'tcx> Ty<'tcx> {
             // These aren't even `Clone`
             ty::Str | ty::Slice(..) | ty::Foreign(..) | ty::Dynamic(..) => false,
 
-            ty::Int(..) | ty::Uint(..) | ty::Float(..) => true,
+            ty::Infer(ty::InferTy::FloatVar(_) | ty::InferTy::IntVar(_))
+            | ty::Int(..)
+            | ty::Uint(..)
+            | ty::Float(..) => true,
 
             // The voldemort ZSTs are fine.
             ty::FnDef(..) => true,