Add missing include.

llvm-svn: 17799
diff --git a/llvm/lib/System/Path.cpp b/llvm/lib/System/Path.cpp
index d582759..a530f28 100644
--- a/llvm/lib/System/Path.cpp
+++ b/llvm/lib/System/Path.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/System/Path.h"
+#include <cassert>
 
 namespace llvm {
 using namespace sys;