Include <cassert> for Cygwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19077 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Debugger/SourceFile.cpp b/lib/Debugger/SourceFile.cpp
index 8e40c88..23144d9 100644
--- a/lib/Debugger/SourceFile.cpp
+++ b/lib/Debugger/SourceFile.cpp
@@ -12,6 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Debugger/SourceFile.h"
+#include <cassert>
+
 using namespace llvm;
 
 /// readFile - Load Filename