fix treatment of literal value in json im-/export

Author: clonker

libyul/AsmJsonImporter.cpp

@@ -198,10 +198,10 @@ Literal AsmJsonImporter::createLiteral(Json const& _node)
 		yulAssert(false, "unknown type of literal");
 
 	solAssert(member(_node, "hexValue").is_string() || member(_node, "value").is_string(), "");
-	if (_node.contains("hexValue"))
-		lit.value = valueOfNumberLiteral(util::asString(util::fromHex(member(_node, "hexValue").get<std::string>())));
+	if (lit.kind == LiteralKind::String && _node.contains("hexValue"))
+		lit.value = valueOfStringLiteral(util::asString(util::fromHex(member(_node, "hexValue").get<std::string>())));
 	else
-		lit.value = valueOfLiteral(member(_node, "value").get<std::string>(), lit.kind);
+		lit.value = valueOfNumberLiteral(member(_node, "value").get<std::string>());
 
 	lit.type = YulString{member(_node, "type").get<std::string>()};