BSE: memory.cc: wrap the CString table in a PersistentStaticInstance<>
BSE: memory.cc: wrap the CString table in a PersistentStaticInstance<>

Enable `static CString` constructs to work reliably.

Signed-off-by: Tim Janik <6ec6ff229c4e1c5bbd5933ee92e6c5832ff023bb@gnu.org>

swesterfeld/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast,swesterfeld/beast,tim-janik/beast,swesterfeld/beast,swesterfeld/beast,tim-janik/beast,swesterfeld/beast,tim-janik/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast