add changelog for PR #2243

Author: IgorStepanov

changelog/typeinfo-gethash.dd

@@ -0,0 +1,7 @@
+`TypeInfo.getHash` now uses `core.internal.hash.hashOf` functions for hash computing
+
+Now `typeid(typeof(var)).getHash(&var)` should be always equal `hashOf(val)`.
+hashOf uses MurmurHash3 algorithm for bitwise hashing, including string hashing.
+Old implementation used polynomial hash for string hashing, which often provided
+lexicographical order of strings in associative array. However AA doesn't guarantee
+some specific order of elements, thus tests which rely on it should be changed.