Apply modernize-pass-by-value.

liblangutil/Exceptions.h

@@ -22,15 +22,16 @@
 
 #pragma once
 
-#include <string>
-#include <utility>
-#include <vector>
-#include <memory>
 #include <libsolutil/Exceptions.h>
 #include <libsolutil/Assertions.h>
 #include <libsolutil/CommonData.h>
 #include <liblangutil/SourceLocation.h>
 
+#include <string>
+#include <utility>
+#include <vector>
+#include <memory>
+
 namespace solidity::langutil
 {
 class Error;