Ensure lower <= upper bound

src/types.cc

Index: src/types.cc
diff --git a/src/types.cc b/src/types.cc
index 9716686f25f1a4a285a8b6b4cf6bfd7f277a7128..17a19b29e4263ac4ef2907c0c9ba45d62baa4cf5 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -240,6 +240,7 @@ int Type::GlbBitset() {
 // Check this <= that.
 bool Type::SlowIs(Type* that) {
   // Fast path for bitsets.
+  if (this->is_none()) return true;
   if (that->is_bitset()) {
     return (this->LubBitset() | that->as_bitset()) == that->as_bitset();
   }
@@ -526,9 +527,13 @@ void Type::TypePrint(FILE* out) {
     }
     PrintF(out, "}");
   } else if (is_constant()) {
-    PrintF(out, "Constant(%p)", static_cast<void*>(*as_constant()));
+    PrintF(out, "Constant(%p : ", static_cast<void*>(*as_constant()));
+    from_bitset(LubBitset())->TypePrint(out);
+    PrintF(")");
   } else if (is_class()) {
-    PrintF(out, "Class(%p)", static_cast<void*>(*as_class()));
+    PrintF(out, "Class(%p < ", static_cast<void*>(*as_class()));
+    from_bitset(LubBitset())->TypePrint(out);
+    PrintF(")");
   } else if (is_union()) {
     PrintF(out, "{");
     Handle<Unioned> unioned = as_union();