Allow Subzero to parse function blocks in parallel.

unittest/BitcodeMunge.cpp

Index: unittest/BitcodeMunge.cpp
diff --git a/unittest/BitcodeMunge.cpp b/unittest/BitcodeMunge.cpp
index c5f0ca9ac8a52484ebdd796904d827a922757421..109d900edeabb9e2b2fdb34c2fc7078a6f3e1cfd 100644
--- a/unittest/BitcodeMunge.cpp
+++ b/unittest/BitcodeMunge.cpp
@@ -26,6 +26,8 @@ void IceTest::SubzeroBitcodeMunger::resetMungeFlags() {
   Flags.setOutFileType(Ice::FT_Iasm);
   Flags.setTargetArch(Ice::Target_X8632);
   Flags.setVerbose(Ice::IceV_Instructions);
+  Flags.setNumTranslationThreads(0);
+  Flags.setVerbose(Ice::IceV_None);
 }
 
 bool IceTest::SubzeroBitcodeMunger::runTest(const uint64_t Munges[],
@@ -34,6 +36,7 @@ bool IceTest::SubzeroBitcodeMunger::runTest(const uint64_t Munges[],
   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);