Pass the size to the allocator so that it may optimize deallocation.
This was seen to significantly reduce the work required in jemalloc,
with about 40% reduction in CPU cycles in the free path.
Note jemalloc >= 5.2 is required to fix a crash with 0 sizes.
2019-05-20 Pádraig Brady <pbrady@fb.com>
* libstdc++-v3/include/ext/new_allocator.h (deallocate): Pass the size
to the deallocator with -fsized-deallocation.
From-SVN: r271409
