To aid in debugging memory leaks, and improve the robustness of log
recovery from crash dumps, statically allocate pglog_msg in the global
scope. This allows logs to be inspected even in cases where a crash
came late in the unload process. It also improves log recovery
robustness by removing the possibility of using a NULL pointer offset
under certain memory corruptions scenarios.
Change-Id: I077198e358570661c2f3adf2704f2c48f4b2f6f8
CRs-Fixed: 2078548