MiMalloc nodump allocator

[duke8253]

When building with MiMalloc, create a no dump heap for each thread, which should behave just like the custom no dump arena for jemalloc. Also updated the license of the file since this is now very different from what facebook had (which this was based on when it all started).

It would be great if @bryancall can run some benchmarks like the ones did for #7501.

[bryancall]

@cmcfarlen will review this

[bryancall]

[bryancall]

Here is a link to the spreadsheet: https://docs.google.com/spreadsheets/d/1oyblceruVgDD9-YhKNfRSEP7Vv5ECN9Rj5O-MlZhYIY/edit?usp=sharing Here are the details of the benchmark runs: https://github.com/bryancall/benchmark/tree/main/mimalloc_reports

[bryancall]

Overall there was a 2.17% reduction in throughput with this PR. Some of that could be noise in the benchmark run.

[duke8253]

[approve ci]