Explicitly confirm that initializing has caused the slab to be resident.
Explicitly confirm that initializing has caused the slab to be resident.

We check for >= from above, but do not check the value from below.  Later, we
confirm that accessing more cores will touch even more memory, and so we would
fail due to testing `0 > 0`, but we can be more explicit about that.

PiperOrigin-RevId: 426506692
Change-Id: I830f35839a30a5202209535915a64ec34de3df39

google/tcmalloc,google/tcmalloc,google/tcmalloc