Don't allow instructions/globals to use alignment > 2**29.

lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h

 //===- NaClBitcodeReader.h ------------------------------------*- C++ -*-===//
 //     Internal NaClBitcodeReader implementation
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
@@ skipping 230 matching lines @@
     return std::error_code(E, BitcodeErrorCategory());
   }
 
   /// Generates the corresponding verbose Message, then generates error.
   std::error_code Error(ErrorType E, const std::string &Message) const;
 
   /// @brief Main interface to parsing a bitcode buffer.
   /// @returns true if an error occurred.
   std::error_code ParseBitcodeInto(Module *M);
 
+  /// Convert alignment exponent (i.e. power of two (or zero)) to the
+  /// corresponding alignment to use. If alignment is too large, it generates
+  /// an error message and returns corresponding error code.
+  std::error_code getAlignmentValue(uint64_t Exponent, unsigned &Alignment);
+
 private:
   // Returns false if Header is acceptable.
   bool AcceptHeader() const {
     return !(Header.IsSupported() ||
              (!AcceptSupportedBitcodeOnly && Header.IsReadable()));
   }
   uint32_t GetPNaClVersion() const {
     return Header.GetPNaClVersion();
   }
   Type *getTypeByID(unsigned ID);
@@ skipping 83 matching lines @@
   std::error_code InitStreamFromBuffer();
   std::error_code InitLazyStream();
   std::error_code FindFunctionInStream(
       Function *F,
       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator);
 };
 
 } // End llvm namespace
 
 #endif