changelog: Add entry about loader symbol searching
## [6.0.0-dev] - unreleased
+- Improved: [[#119](https://github.com/ethereum/evmc/pull/119)]
+ EVMC loader symbol searching has been generalized.
+
## [5.2.0] - 2018-08-28
- Feature: [[#81](https://github.com/ethereum/evmc/pull/81)]
