Appease MSVC

Apply a similar fix to the one in r269006 to LiveIntervalTest.cpp.

llvm-svn: 269009

llvm/unittests/MI/LiveIntervalTest.cpp

@@ -3,6 +3,7 @@
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/MIRParser/MIRParser.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/Support/MemoryBuffer.h"