Merge pull request #12775 from ethereum/refactorDataFlowAnalyzer

Refactor data flow analyzer state access.

test/libyul/KnowledgeBaseTest.cpp

@@ -58,7 +58,7 @@ protected:
 		for (auto const& [name, expression]: m_ssaValues.values())
 			m_values[name].value = expression;
 
-		return KnowledgeBase(m_dialect, m_values);
+		return KnowledgeBase(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_values, _var); });
 	}
 
 	EVMDialect m_dialect{EVMVersion{}, true};