trans: Decide whether to load volatile_store's argument based on its ArgType.

src/librustc_trans/trans/intrinsic.rs

@@ -589,10 +589,10 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
         },
         (_, "volatile_store") => {
             let tp_ty = *substs.types.get(FnSpace, 0);
-            let val = if type_is_immediate(bcx.ccx(), tp_ty) {
-                from_immediate(bcx, llargs[1])
-            } else {
+            let val = if fn_ty.args[1].is_indirect() {
                 Load(bcx, llargs[1])
+            } else {
+                from_immediate(bcx, llargs[1])
             };
             let ptr = PointerCast(bcx, llargs[0], val_ty(val).ptr_to());
             let store = VolatileStore(bcx, val, ptr);