Add abilities to generate bitcode buffers from munged bitcode.

include/llvm/Bitcode/NaCl/NaClBitcodeParser.h

Index: include/llvm/Bitcode/NaCl/NaClBitcodeParser.h
diff --git a/include/llvm/Bitcode/NaCl/NaClBitcodeParser.h b/include/llvm/Bitcode/NaCl/NaClBitcodeParser.h
index d9370335bd1d4e79e9a0577064f48c93c5df5c2a..eed361d6b392cdcf2950586f658d18a99a5c41ab 100644
--- a/include/llvm/Bitcode/NaCl/NaClBitcodeParser.h
+++ b/include/llvm/Bitcode/NaCl/NaClBitcodeParser.h
@@ -457,6 +457,11 @@ public:
   /// Can be called multiple times to parse multiple blocks.
   bool Parse();
 
+  /// Returns true if at end of buffer.
+  bool AtEndOfStream() const {
+    return Record.GetCursor().AtEndOfStream();
+  }
+
   // Called once the bitstream reader has entered the corresponding
   // subblock.  Argument NumWords is set to the number of words in the
   // corresponding subblock.