Add a command-line option to allow function names with the "rs" prefix (--allow-rs-prefix).  When not specified, user-defined functions with that prefix will be treated as an error.

Change-Id: Ieefc8bb55d61980241d5392ffb32770a303ce6a7
diff --git a/slang.hpp b/slang.hpp
index 0dbf00c..4f4ff44 100644
--- a/slang.hpp
+++ b/slang.hpp
@@ -131,7 +131,8 @@
                                    mPragmas,
                                    mOS.take(),
                                    mOutputType,
-                                   *mSourceMgr));
+                                   *mSourceMgr,
+                                   mAllowRSPrefix));
 
         return;
     }
@@ -144,7 +145,8 @@
                                      mPragmas,
                                      mOS.take(),
                                      mOutputType,
-                                     *mSourceMgr));
+                                     *mSourceMgr,
+                                     mAllowRSPrefix));
 
         return;
     }
@@ -158,6 +160,8 @@
     /* Output stream */
     llvm::OwningPtr<llvm::raw_ostream> mOS;
 
+    bool mAllowRSPrefix;
+
 public:
     static const std::string TargetDescription;
 
@@ -181,6 +185,10 @@
 
     bool setOutput(const char* outputFile);
 
+    inline void allowRSPrefix() {
+        mAllowRSPrefix = true;
+    }
+
     int compile();
 
     bool reflectToJava(const char* outputPackageName);