Version 0.1.31

Changes

Updated mimalloc submodule to v2.0.7. Changelog from upstream:

Initial support for Valgrind for leak testing and heap block overflow detection. Initial support for attaching heaps to a speficic memory area (only in v2). Fix realloc behavior for zero size blocks, remove restriction to integral multiple of the alignment in alloc_align, improved aligned allocation performance, reduced contention with many threads on few processors (thank you @dposluns!), vs2022 support, support pkg-config, .