Subzero: Add locking to prepare for multithreaded translation.

src/IceTranslator.h

Index: src/IceTranslator.h
diff --git a/src/IceTranslator.h b/src/IceTranslator.h
index 9aa56aaec8e3cfd4d44d45cccd9c3c3ad3cbc717..a0c04098c3f3f73a403ac65b2d7bb45f099af308 100644
--- a/src/IceTranslator.h
+++ b/src/IceTranslator.h
@@ -67,7 +67,7 @@ public:
   /// Prefix to name unnamed names. Errors are put on Ostream.
   /// Returns true if there isn't a potential conflict.
   bool checkIfUnnamedNameSafe(const IceString &Name, const char *Kind,
-                              const IceString &Prefix, Ostream &Stream);
+                              const IceString &Prefix);
 
 protected:
   GlobalContext *Ctx;