Delete atomic_inc
This was a little weird: I deleted the definition first, and everything
compiled because all the usages now are behind ifdefs that we don't test
regularly. In the interest of not ruffling feathers over deleting this
code, I just went ahead and made the changes. I would like to suggest
deleting all this stuff, especially the GOOGLE_HEAP_PROFILER stuff, for
which the make target has been deleted for a long time.
Again, all the usage sites are using the default memory order specifier,
which is memory_order_seq_cst. They could stand to be relaxed, but I
didn't find it worthwhile.
I'd also like to replace atomic_acquire_load and atomic_release_store
with portable and correct alternatives. We really just shouldn't be
rolling our own atomic primitives.
Differential Revision:
D909903