Split vendored sources into their own crate.

Added

• Support building mimalloc v3 (lnslyosl)
  • Using this version breaks most of the high-level bindings in mimalloc-rich
• Support allocator-api v0.2, v0.3, and v0.4, all at once (ynxstnuk)
  • Enabled by default with mimalloc-rich/allocator-api2-all feature.

Changes

• Deprecate the MiHeap API, as it will need to be rewritten when mimalloc v3 support is added (mztqvrpx)
• Rename mimalloc-rich-sys/override feature to mimalloc-rich-sys/override-libc-malloc (zzxlwnyv)
• Split vendored sources into own crate (pvvpzosl)
  • Will reduce download time when there are multiple mimalloc versions.
  • Will reduces download time when building against a system library (not currently supported)
• Rename mimalloc-rich-sys/vendored-mimalloc to mimalloc-rich-sys/vendored (nqpsmsnn)

Associated Versions

• mimalloc@2.5.2
• mimalloc@3.5.3
• mimalloc-rich-src-v2@1.5.200
• mimalloc-rich-src-v3@1.5.300

Initial Release

Initial release.

Code largely taken from DuckLogic, but cleaned up for public release.

Uses mimalloc v2.5.2, as v3 wasn't stable when this code was originally written.

Uses allocator-api2 v0.2.* as that is what hashbrown v0.17 and bumpalo v3 both use.