Install notion of diagnostic handler into PNaCl bitcode readers.

unittests/Bitcode/NaClMungeWriteErrorTests.cpp

 //===- llvm/unittest/Bitcode/NaClMungeWriteErrorTests.cpp -----------------===//
 //     Tests parser for PNaCl bitcode instructions.
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ skipping 48 matching lines @@
     "          |                             |                   // BlockID "
     "= 12\n"
     "      56:0|    3: <1, 1>                |    blocks 1;\n"
     "          |                             |  %b0:\n"
     "      58:4|    3: <10>                  |    ret void;\n"
     "      60:2|  0: <65534>                 |  }\n"
     "      64:0|0: <65534>                   |}\n"
     ;
 
 const char *UnableToContinue =
-      "Error: Unable to generate bitcode file due to write errors\n";
+    "error: Unable to generate bitcode file due to write errors\n";
 
 const char *NoErrorRecoveryMessages = "";
 
 // Runs write munging tests on BitcodeRecords with the given Edits. It
 // then parses the written bitcode.  ErrorMessages is the expected
 // error messages logged by the write munging, when no error recovery
 // is allowed. ErrorRecoveryMessages are messages, in addition to
 // ErrorMessages, when the writer applies error recovery.
 void CheckParseEdits(const uint64_t *Edits, size_t EditsSize,
                      std::string ErrorMessages,
@@ skipping 753 matching lines @@
       "       1: [65535, 4294967295, 3]\n"
       "         3: [8, 1, 0, 0, 0]\n"
       "         1: [65535, 12, 2]\n"
       "           3: [1, 1]\n"
       "           3: [10]\n"
       "         0: [65534]\n"
       "       0: [65534]\n");
 }
 
 } // end of namespace naclmungetest