[PATCH v3 0/4] MR4313: MSVCRT _(w)environ[] has a separate allocation chunk for each entry.

[eric pouech (＠epo)]

_(w)environ[] do have a distinct allocation chunk for each entry, so
that _(w)environ[i] pointer and (pointed) string don't change when
updating/deleting any other entry.

Proposed implementation still differs from native:
- allocation is done on process heap, while native uses msvcrt's heap
- first ANSI allocated _environ[] doesn't have per entry allocation.
  This is only activated after a change (update/deletion) to _environ[]
  is made.

--
  v3: msvcrt: Let each _environ[] entry have a distinct allocation block.
      msvcrt/tests: Add tests about intricating kernel32 and msvcrt env calls.
      msvcrt/tests: Add tests about allocation of environment entries.
      msvcrt: Improve environment tests (initial conditions).

https://gitlab.winehq.org/wine/wine/-/merge_requests/4313