Add virtual destructors on base classes.

test/ExecutionFramework.h

@@ -53,6 +53,7 @@ class ExecutionFramework
 
 public:
 	ExecutionFramework();
+	virtual ~ExecutionFramework() = default;
 
 	virtual bytes const& compileAndRunWithoutCheck(
 		std::string const& _sourceCode,

test/libsolidity/AnalysisFramework.h

@@ -52,6 +52,7 @@ protected:
 		bool _insertVersionPragma = true,
 		bool _allowMultipleErrors = false
 	);
+	virtual ~AnalysisFramework() = default;
 
 	SourceUnit const* parseAndAnalyse(std::string const& _source);
 	bool success(std::string const& _source);