Enable yul optimizer by default.

libsolidity/interface/CompilerStack.cpp

@@ -230,12 +230,6 @@ bool CompilerStack::parse()
 	if (SemVerVersion{string(VersionString)}.isPrerelease())
 		m_errorReporter.warning("This is a pre-release compiler version, please do not use it in production.");
 
-	if (m_optimiserSettings.runYulOptimiser)
-		m_errorReporter.warning(
-			"The Yul optimiser is still experimental. "
-			"Do not use it in production unless correctness of generated code is verified with extensive tests."
-		);
-
 	vector<string> sourcesToParse;
 	for (auto const& s: m_sources)
 		sourcesToParse.push_back(s.first);

libsolidity/interface/OptimiserSettings.h

@@ -54,19 +54,15 @@ struct OptimiserSettings
 		s.runDeduplicate = true;
 		s.runCSE = true;
 		s.runConstantOptimiser = true;
-		// The only disabled ones
-		s.optimizeStackAllocation = false;
-		s.runYulOptimiser = false;
+		s.runYulOptimiser = true;
+		s.optimizeStackAllocation = true;
 		s.expectedExecutionsPerDeployment = 200;
 		return s;
 	}
-	/// Standard optimisations plus yul and stack optimiser.
+	/// Full optimisations. Currently an alias for standard optimisations.
 	static OptimiserSettings full()
 	{
-		OptimiserSettings s = standard();
-		s.optimizeStackAllocation = true;
-		s.runYulOptimiser = true;
-		return s;
+		return standard();
 	}
 
 	bool operator==(OptimiserSettings const& _other) const

libsolidity/interface/StandardCompiler.cpp

@@ -480,8 +480,7 @@ boost::variant<OptimiserSettings, Json::Value> parseOptimizerSettings(Json::Valu
 			return *error;
 		if (auto error = checkOptimizerDetail(details, "yul", settings.runYulOptimiser))
 			return *error;
-		if (settings.runYulOptimiser)
-			settings.optimizeStackAllocation = true;
+		settings.optimizeStackAllocation = settings.runYulOptimiser;
 		if (details.isMember("yulDetails"))
 		{
 			if (!settings.runYulOptimiser)