This serie: - adds a couple of msvcrt env tests (mainly env block inheritance) - introduces env tests for ucrtbase - reimplement most of the env related functions to mimic native behavior (basically when env is modified, native crt uses a per-variable entry allocation block (instead of having pointers inside a single chunk of memory). This fixes programs which keep a pointer on returned getenv() string and expect that pointer content is not modified when other variables in env are modified.
@piotr: from previous version - I dropped the synchronization of _environ and _wenviron hence requiring the duplication of most of the code in ansi/unicode versions - I also tested the changes with unicode crt startup code (you can find in [1] this MR extended with this test code but I don't think we want to push it upstream) - there are some init code changes because of ucrtbase tests and unicode crt startup tests
[1] https://gitlab.winehq.org/epo/wine/-/tree/mr-crt-env-full?ref_type=heads