Allow Subzero to parse function blocks in parallel.

unittest/BitcodeMunge.cpp

 //===- BitcodeMunge.cpp - Subzero Bitcode Munger ----------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Test harness for testing malformed bitcode files in Subzero.
 //
 //===----------------------------------------------------------------------===//
 
 #include "BitcodeMunge.h"
 #include "IceCfg.h"
 #include "IceClFlags.h"
 #include "PNaClTranslator.h"
 #include "IceTypes.h"
 
 namespace IceTest {
 
 void IceTest::SubzeroBitcodeMunger::resetMungeFlags() {
   Flags.setAllowErrorRecovery(true);
   Flags.setGenerateUnitTestMessages(true);
   Flags.setOptLevel(Ice::Opt_m1);
   Flags.setOutFileType(Ice::FT_Iasm);
   Flags.setTargetArch(Ice::Target_X8632);
-  Flags.setVerbose(Ice::IceV_Instructions);
+  Flags.setNumTranslationThreads(0);
+  Flags.setParseParallel(false);
 }
 
 bool IceTest::SubzeroBitcodeMunger::runTest(const uint64_t Munges[],
                                             size_t MungeSize,
                                             bool DisableTranslation) {
   const bool AddHeader = true;
   setupTest(Munges, MungeSize, AddHeader);
   Ice::GlobalContext Ctx(DumpStream, DumpStream, DumpStream, nullptr);
+  Ctx.startWorkerThreads();
   Ice::PNaClTranslator Translator(&Ctx);
   const char *BufferName = "Test";
   Flags.setDisableTranslation(DisableTranslation);
   Translator.translateBuffer(BufferName, MungedInput.get());
+  Ctx.waitForWorkerThreads();
 
   cleanupTest();
   return Translator.getErrorStatus().value() == 0;
 }
 
 } // end of namespace IceTest