calloc is generally faster than zeroing separately after a regular
allocation. Our allocator API exposed an allocation call with "calloc"
in the name that didn't actually use "calloc" because it had an
alignment argument (there is no standardized calloc-with-alignment
provided by the OS). However, we can still use calloc internally if
the alignment fits within the default. That just aligns the function
better with performance expectations.
Pull Request: https://projects.blender.org/blender/blender/pulls/139749
d94ef63cb3