Add change log entry for the 9.2 compat changes

Author: Ericson2314

CHANGELOG.md

@@ -1,5 +1,20 @@
 ## Changes in 3.2.6:
 
+ * Support for the GHC 9.2.
+
+   The array access primops now read/write with the fixed-sized numeric
+   type corresponding to the width of the data accessed. Additionally,
+   the primops to convert to and from fixed-sized numeric types have
+   been given new names.
+
+   9.2 isn't cut yet, so these changes are somewhat speculative, but
+   unfortunately GHC must used a released version of Alex (and Happy) at
+   all times until further changes have been made, so we must make the
+   release to actually implement these changes in GHC.
+
+   If the final GHC 9.2 ends up being different, this release will be
+   marked broken to make it less likely people use it by accident.
+
 ## Changes in 3.2.5:
 
  * Build fixes for GHC 8.8.x