[serializer] Add API to warm up startup snapshot with an additional script.

src/globals.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_GLOBALS_H_
 #define V8_GLOBALS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 457 matching lines @@
 };
 
 enum GarbageCollector { SCAVENGER, MARK_COMPACTOR };
 
 enum Executability { NOT_EXECUTABLE, EXECUTABLE };
 
 enum VisitMode {
   VISIT_ALL,
   VISIT_ALL_IN_SCAVENGE,
   VISIT_ALL_IN_SWEEP_NEWSPACE,
-  VISIT_ONLY_STRONG
+  VISIT_ONLY_STRONG,
+  VISIT_ONLY_STRONG_FOR_SERIALIZATION
 };
 
 // Flag indicating whether code is built into the VM (one of the natives files).
 enum NativesFlag { NOT_NATIVES_CODE, EXTENSION_CODE, NATIVES_CODE };
 
 // JavaScript defines two kinds of 'nil'.
 enum NilValue { kNullValue, kUndefinedValue };
 
 // ParseRestriction is used to restrict the set of valid statements in a
 // unit of compilation.  Restriction violations cause a syntax error.
@@ skipping 537 matching lines @@
   return static_cast<uint32_t>(bit_cast<uintptr_t>(address) >>
                                kPointerSizeLog2);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 namespace i = v8::internal;
 
 #endif  // V8_GLOBALS_H_