Add missing file to last changelist, for NaN Dates.

src/runtime.cc

Index: src/runtime.cc
===================================================================
--- src/runtime.cc	(revision 2600)
+++ src/runtime.cc	(working copy)
@@ -4920,7 +4920,7 @@
   ASSERT(args.length() == 1);
 
   CONVERT_DOUBLE_CHECKED(x, args[0]);
-  char* zone = OS::LocalTimezone(x);
+  const char* zone = OS::LocalTimezone(x);
   return Heap::AllocateStringFromUtf8(CStrVector(zone));
 }