Move part of scanner.* into scanner-base.* for reuse in preparser scanner.

src/checks.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 80 matching lines @@
 
 void API_Fatal(const char* location, const char* format, ...) {
   i::OS::PrintError("\n#\n# Fatal error in %s\n# ", location);
   va_list arguments;
   va_start(arguments, format);
   i::OS::VPrintError(format, arguments);
   va_end(arguments);
   i::OS::PrintError("\n#\n\n");
   i::OS::Abort();
 }
+
+
+namespace v8 { namespace internal {
+
+  bool EnableSlowAsserts() { return FLAG_enable_slow_asserts; }
+
+  intptr_t HeapObjectTagMask() { return kHeapObjectTagMask; }
+
+} }  // namespace v8::internal