Fix a build failure with perf: Add a missing include to llvm/Support/ManagedStatic.h

It was failing with
PerfJITEventListener.cpp:489:7: error: 'ManagedStatic' in namespace 'llvm' does not name a template type
 llvm::ManagedStatic<PerfJITEventListener> PerfListener;

llvm/lib/ExecutionEngine/PerfJITEvents/PerfJITEventListener.cpp

@@ -24,6 +24,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Errno.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/Path.h"