Add error recovery for abbreviations outside blocks in bitcode.

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 645 matching lines @@
     Terminator
   };
   CheckDumpEdits(
       ARRAY(Edit),
       "Error (Block 17): Malformed abbreviation found: 2: [65533, 3, 1, 10,"
       " 1, 15]\n",
       NoErrorRecoveryMessages,
       ExpectedDumpedBitcode);
 }
 
+// Show what happens if an abbreviation definition is defined outside a block.
+TEST(NaClMungeWriteErrorTests, AbbreviationNotInBlock) {
+  // Add abbreviation before all records.
+  const uint64_t Edit[] = {
+    0, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 1,
+    1, 10,                          // lit(10)
+    Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block unknown): Abbreviation definition not in block: 2:"
+      " [65533, 1, 1, 10]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
+
 } // end of namespace naclmungetest