Add #include

llvm-svn: 4291
diff --git a/llvm/lib/Support/Timer.cpp b/llvm/lib/Support/Timer.cpp
index fb38fcb..d0ce71f 100644
--- a/llvm/lib/Support/Timer.cpp
+++ b/llvm/lib/Support/Timer.cpp
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <iostream>
 #include <algorithm>
+#include <functional>
 
 static TimerGroup *DefaultTimerGroup = 0;
 static TimerGroup *getDefaultTimerGroup() {