[libyul] Fix false-negative maybe-uninitialized warning on gcc.

Author: aarlt

libyul/optimiser/ForLoopConditionIntoBody.cpp

@@ -32,8 +32,9 @@ void ForLoopConditionIntoBody::run(OptimiserStepContext& _context, Block& _ast)
 
 void ForLoopConditionIntoBody::operator()(ForLoop& _forLoop)
 {
+	std::optional<BuiltinHandle> booleanNegationFunctionHandle = m_dialect.booleanNegationFunctionHandle();
 	if (
-		m_dialect.booleanNegationFunctionHandle() &&
+		booleanNegationFunctionHandle &&
 		!std::holds_alternative<Literal>(*_forLoop.condition) &&
 		!std::holds_alternative<Identifier>(*_forLoop.condition)
 	)
@@ -47,7 +48,7 @@ void ForLoopConditionIntoBody::operator()(ForLoop& _forLoop)
 				std::make_unique<Expression>(
 					FunctionCall {
 						debugData,
-						BuiltinName{debugData, *m_dialect.booleanNegationFunctionHandle()},
+						BuiltinName{debugData, *booleanNegationFunctionHandle},
 						util::make_vector<Expression>(std::move(*_forLoop.condition))
 					}
 				),

libyul/optimiser/UnusedPruner.cpp

@@ -81,6 +81,7 @@ void UnusedPruner::operator()(Block& _block)
 				[&](NameWithDebugData const& _typedName) { return used(_typedName.name); }
 			))
 			{
+				std::optional<BuiltinHandle> discardFunctionHandle = m_dialect.discardFunctionHandle();
 				if (!varDecl.value)
 					statement = Block{std::move(varDecl.debugData), {}};
 				else if (
@@ -91,10 +92,10 @@ void UnusedPruner::operator()(Block& _block)
 					subtractReferences(ReferencesCounter::countReferences(*varDecl.value));
 					statement = Block{std::move(varDecl.debugData), {}};
 				}
-				else if (varDecl.variables.size() == 1 && m_dialect.discardFunctionHandle())
+				else if (varDecl.variables.size() == 1 && discardFunctionHandle)
 					statement = ExpressionStatement{varDecl.debugData, FunctionCall{
 						varDecl.debugData,
-						BuiltinName{varDecl.debugData, *m_dialect.discardFunctionHandle()},
+						BuiltinName{varDecl.debugData, *discardFunctionHandle},
 						{*std::move(varDecl.value)}
 					}};
 			}