Second step towards loading the core library scripts directly from the sources

runtime/vm/symbols.h

Index: runtime/vm/symbols.h
===================================================================
--- runtime/vm/symbols.h	(revision 22375)
+++ runtime/vm/symbols.h	(working copy)
@@ -341,6 +341,9 @@
   static const String& Backtick() {
     return *(symbol_handles_[kNullCharId + '`']);
   }
+  static const String& Slash() {
+    return *(symbol_handles_[kNullCharId + '/']);
+  }
 
   // Access methods for symbol handles stored in the vm isolate.
 #define DEFINE_SYMBOL_HANDLE_ACCESSOR(symbol, literal)                         \