Enable mutual recursion on effGetProgramName()

PG-8X in REAPER has the same mutual recursion limitation the Voxengo
plugins had in Renoise, but with `effGetProgramName()` instead of
`effGetProgram()`.

CHANGELOG.md

@@ -70,6 +70,7 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 - Also fixed _DMG_ VST3 plugins freezing in **REAPER** when restoring multiple
   instances of the plugin at once while the FX window is open and the GUI is
   visible.
+- Fixed the _PG-8X_ VST2 plugin freezing in **REAPER** when loading the plugin.
 - Fixed _Voxengo_ VST2 plugins in **Renoise** freezing when loading a project or
   when otherwise restoring plugin state.
 - Fixed logging traces in the VST2 audio processing functions causing