Fix repr() for UncheckedArray (#9385)

lib/system/hti.nim

@@ -58,7 +58,7 @@ type
     tyUInt64,
     tyOptAsRef, tyUnused1, tyUnused2,
     tyVarargsHidden,
-    tyUnusedHidden,
+    tyUncheckedArray,
     tyProxyHidden,
     tyBuiltInTypeClassHidden,
     tyUserTypeClassHidden,

lib/system/repr.nim

@@ -278,6 +278,8 @@ when not defined(useNimRtl):
     of tyProc, tyPointer:
       if cast[PPointer](p)[] == nil: add result, "nil"
       else: add result, reprPointer(cast[PPointer](p)[])
+    of tyUncheckedArray:
+      add result, "[...]"
     else:
       add result, "(invalid data!)"
     inc(cl.recdepth)