And make `core:terminal` use it so that `core:log` can be imported with `-default-to-nil-allocator`,
in which the actual allocator is set up in `main()`.
Windows was tricky because of the utf-8 <> utf-16 conversion, so we use some temporary stack buffers for that purpose,
limiting the non-allocating version there to 512 utf-16 characters each for the key and environment value.
In general the value is (obviously) limited to the size of the supplied buffer, and a `.Buffer_Full` error is returned
if that buffer is insufficient. If the key is not found, the procedure returns `.Env_Var_Not_Found`.
TODO:
- Factor out buffer-backed utf8 + utf16 conversion to `core:sys/util` to more easily apply this pattern.
- Add similar `lookup_env` and `get_env` procedures to `core:os/os2`.
Fixes#5336
`open` specifies the `mode` argument as vararg (presumably to make it
optional). varargs actually have rules about casting, in this case the
rule that any integer arg of size <= 4 has to be casted to `i32` before
passing it.
Not doing that implicit cast makes the permissions wrong or not apply at
all.
Updated core with some path related functions and did some minor code cleanup.
Most of the standard library function is just a matter of copy what is there for the other BSDs.
Jeroen van Rijn
Feoramund
Colin Davidson
Yuriy Grynevych
Laytan Laats
gingerBill
Andreas T Jonsson