remove undetectable strings

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 523b819a37fe4d7d038ba3a0be40e0825e6e4924..8feec8f3b59e5ce8c0d3e37a141a896e74909c4c 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -2716,12 +2716,6 @@ bool Heap::CreateInitialMaps() {
       set_native_source_string_map(Map::cast(obj));
     }
 
-    ALLOCATE_VARSIZE_MAP(STRING_TYPE, undetectable_string)
-    undetectable_string_map()->set_is_undetectable();
-
-    ALLOCATE_VARSIZE_MAP(ONE_BYTE_STRING_TYPE, undetectable_one_byte_string);
-    undetectable_one_byte_string_map()->set_is_undetectable();
-
     ALLOCATE_VARSIZE_MAP(FIXED_DOUBLE_ARRAY_TYPE, fixed_double_array)
     ALLOCATE_VARSIZE_MAP(BYTE_ARRAY_TYPE, byte_array)
     ALLOCATE_VARSIZE_MAP(FREE_SPACE_TYPE, free_space)