Fix the NaCl bitstream reader to report fatal errors.

include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h

Index: include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h
diff --git a/include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h b/include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h
index 03438e39c67308b7abd73dc45f1a71df4b699bab..31a5c4733636811b5e2828cf94fe335751303898 100644
--- a/include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h
+++ b/include/llvm/Bitcode/NaCl/NaClBitcodeMunge.h
@@ -139,6 +139,8 @@ protected:
   std::string FatalBuffer;
   // The stream to write the fatal message to.
   raw_string_ostream FatalStream;
+  // The stack of maximum abbreviation indices allowed by block enter record.
+  SmallVector<uint64_t, 3> AbbrevIndexLimitStack;
 
   // Records that an error occurred, and returns stream to print error
   // message to.
@@ -197,7 +199,8 @@ public:
   /// Creates a bitcode munger, based on the given array of values.
   NaClObjDumpMunger(const uint64_t Records[], size_t RecordsSize,
                     uint64_t RecordTerminator)
-      : NaClBitcodeMunger(Records, RecordsSize, RecordTerminator) {}
+      : NaClBitcodeMunger(Records, RecordsSize, RecordTerminator),
+        RunAsDeathTest(false) {}
 
   /// Runs function NaClObjDump on the sequence of records associated
   /// with the instance. The memory buffer containing the bitsequence
@@ -215,6 +218,18 @@ public:
                             NoAssembly);
   }
 
+  /// Returns true if running as death test.
+  bool getRunAsDeathTest() const {
+    return RunAsDeathTest;
+  }
+
+  /// Sets death test flag. When true, output will be redirected to
+  /// the errs() (rather than buffered) so that the test can be
+  /// debugged.
+  void setRunAsDeathTest(bool NewValue) {
+    RunAsDeathTest = NewValue;
+  }
+
   /// Same as above except it runs function NaClObjDump with flags
   /// NoRecords and NoAssembly set to false, and AddHeader set to true.
   bool runTest(const char *TestName) {
@@ -260,6 +275,11 @@ public:
                         size_t MungesSize) {
     return runTestWithFlags(TestName, Munges, MungesSize, true, true, true);
   }
+
+private:
+  // Flag to redirect dump stream if running death test.
+  bool RunAsDeathTest;
+
 };
 
 // Class to run tests for function NaClParseBitcodeFile.