Add missing cassert includes

Bug: http://b/175635923
Test: treehugger
Change-Id: I8caf940f7b6e2fdd921516efea4aed14e0c2afb7
diff --git a/cmds/idmap2/libidmap2/CommandLineOptions.cpp b/cmds/idmap2/libidmap2/CommandLineOptions.cpp
index 5b0ae92..8129d99 100644
--- a/cmds/idmap2/libidmap2/CommandLineOptions.cpp
+++ b/cmds/idmap2/libidmap2/CommandLineOptions.cpp
@@ -17,6 +17,7 @@
 #include "idmap2/CommandLineOptions.h"
 
 #include <algorithm>
+#include <cassert>
 #include <iomanip>
 #include <iostream>
 #include <memory>