Fix #1341.

src/boot/boot.janet

@@ -2127,6 +2127,7 @@
      'upscope expandall})
 
   (defn dotup [t]
+    (if (= nil (next t)) (break ()))
     (def h (in t 0))
     (def s (in specs h))
     (def entry (or (dyn h) {}))

test/suite-boot.janet

@@ -968,4 +968,8 @@
   (identity a))
 (assert (= [1 2 3] (regress-1330)) "regression 1330")
 
+# Issue 1341
+(assert (= () '() (macex '())) "macex ()")
+(assert (= '[] (macex '[])) "macex []")
+
 (end-suite)