Update subzero bitcode parser to use new API for bitstream reading.

src/PNaClTranslator.cpp

 //===- subzero/src/PNaClTranslator.cpp - ICE from bitcode -----------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the PNaCl bitcode file to Ice, to machine code
@@ skipping 2977 matching lines @@
 
   // Read header and verify it is good.
   NaClBitcodeHeader Header;
   if (Header.Read(MemObj.get()) || !Header.IsSupported()) {
     errs() << "Invalid PNaCl bitcode header.\n";
     ErrorStatus.assign(EC_Bitcode);
     return;
   }
 
   // Create a bitstream reader to read the bitcode file.
-  NaClBitstreamReader InputStreamFile(MemObj.release(), Header.getHeaderSize());
+  NaClBitstreamReader InputStreamFile(MemObj.release(), Header);
   NaClBitstreamCursor InputStream(InputStreamFile);
 
   TopLevelParser Parser(*this, InputStream, ErrorStatus);
   int TopLevelBlocks = 0;
   while (!InputStream.AtEndOfStream()) {
     if (Parser.Parse()) {
       ErrorStatus.assign(EC_Bitcode);
       return;
     }
     ++TopLevelBlocks;
   }
 
   if (TopLevelBlocks != 1) {
     errs() << IRFilename
            << ": Contains more than one module. Found: " << TopLevelBlocks
            << "\n";
     ErrorStatus.assign(EC_Bitcode);
   }
   if (InputStreamFile.getBitcodeBytes().getExtent() % 4 != 0) {
     errs() << IRFilename
            << ": Bitcode stream should be a multiple of 4 bytes in length.\n";
     ErrorStatus.assign(EC_Bitcode);
     return;
   }
 }
 
 } // end of namespace Ice