Install notion of diagnostic handler into PNaCl bitcode readers.

unittests/Bitcode/NaClMungeTest.h

 //===- llvm/unittest/Bitcode/NaClMungeTest.h - Test munging utils ---------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 // Contains common utilities used in bitcode munge tests.
 
 #ifndef LLVM_UNITTEST_BITCODE_NACLMUNGETEST_H
 #define LLVM_UNITTEST_BITCODE_NACLMUNGETEST_H
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Bitcode/NaCl/NaClBitcodeMunge.h"
 
 #include "gtest/gtest.h"
 
 namespace naclmungetest {
 
 const uint64_t Terminator = 0x5768798008978675LL;
 
 #define ARRAY(name) name, array_lengthof(name)
 
 #define ARRAY_TERM(name) ARRAY(name), Terminator
 
+// Removes error severity prefices, if present, for each line in the message.
+// Returns the stripped result.
+std::string stripErrorPrefix(const std::string &Message);
+
 inline std::string stringify(llvm::NaClMungedBitcode &MungedBitcode) {
   std::string Buffer;
   llvm::raw_string_ostream StrBuf(Buffer);
   MungedBitcode.print(StrBuf);
   return StrBuf.str();
 }
 
 inline std::string stringify(llvm::NaClBitcodeMunger &Munger) {
   return stringify(Munger.getMungedBitcode());
 }
 
 } // end of namespace naclmungetest
 
 #endif // end LLVM_UNITTEST_BITCODE_NACLMUNGETEST_H