Merge pull request #9252 from ethereum/develop

Merge develop into breaking.

libsolidity/ast/AST.cpp

@@ -492,12 +492,7 @@ DeclarationAnnotation& Declaration::annotation() const
 bool VariableDeclaration::isLValue() const
 {
 	// Constant declared variables are Read-Only
-	if (isConstant())
-		return false;
-	// External function arguments of reference type are Read-Only
-	if (isExternalCallableParameter() && dynamic_cast<ReferenceType const*>(type()))
-		return false;
-	return true;
+	return !isConstant();
 }
 
 bool VariableDeclaration::isLocalVariable() const