Remove unused RegExp private symbols.

src/heap/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 327 matching lines @@
   V(observed_symbol)                        \
   V(premonomorphic_symbol)                  \
   V(promise_combined_deferred_symbol)       \
   V(promise_debug_marker_symbol)            \
   V(promise_has_handler_symbol)             \
   V(promise_on_resolve_symbol)              \
   V(promise_on_reject_symbol)               \
   V(promise_raw_symbol)                     \
   V(promise_status_symbol)                  \
   V(promise_value_symbol)                   \
-  V(regexp_flags_symbol)                    \
-  V(regexp_source_symbol)                   \
   V(sealed_symbol)                          \
   V(stack_trace_symbol)                     \
   V(string_iterator_iterated_string_symbol) \
   V(string_iterator_next_index_symbol)      \
   V(uninitialized_symbol)
 
 #define PUBLIC_SYMBOL_LIST(V)                 \
   V(has_instance_symbol, Symbol.hasInstance)  \
   V(iterator_symbol, Symbol.iterator)         \
   V(match_symbol, Symbol.match)               \
@@ skipping 2360 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_