Remove four counter increments out of the allocation path.

- This change removes the four allocation counters (the number of
bytes allocated, the number of objects allocated, the number of bytes
allocated ever, the number of objects allocated ever) from the
dlmalloc space allocation path. Now those counter values are computed
on the fly based on a combination of the two new counters that are
incremented by the GC side (the number of bytes freed ever and the
number of objects freed ever) and mspace_inspect_all() calls.

- This results in a 1-2% speedup (though with some noise) in Ritz
MemAllocTest on Nexus 4.

Bug: 9986565
Change-Id: Id9a8e05a745ac1e5ea7a2b5fd9319814a9d4af13