Add a "show uma" command to DDB, which prints out the current stats for available UMA zones.  Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box.
Add a "show uma" command to DDB, which prints out the current stats for
available UMA zones.  Quite useful for post-mortem debugging of memory
leaks without a dump device configured on a panicked box.

MFC after:	2 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase