- C compilation flows didn't hold an exclusive lock on the cache manifest file when writing to it in all cases
- On windows, explicitly unlock the file lock before closing it
There are still a few occurrences of "stage1" in the standard library
and self-hosted compiler source, however, these instances need a bit
more careful inspection to ensure no breakage.
When testing with
```
stage4/bin/zig test ../test/behavior.zig -I../test -ofmt=c -target x86_64-windows
```
previously, one would see this message:
```
error: lld-link: subsystem must be defined
```
Now, `--subsystem console` as well as `-lntdll -lkernel32` are on the
`zig run` line, producing a binary.
In ea9ad1e85dd5e2ba18e7d55f7a7f9694282159f1, I incorrectly applied
boolean logic to one of the pieces of logic, resulting in a regression
in translate-c.
Instead of checking for absolute paths and current working directories
in various file system operations, there is one simple solution: allow
overriding `std.fs.cwd` on WASI.
os.realpath is back to causing a compile error when used on WASI. This
caused a compile error in the Sema handling of `@src()`. The compiler
should never call realpath, so the commit that made this change is
reverted (95ab942184427e7c9b840d71f4d093931e3e48fb). If this breaks
debug info, a different strategy is needed to solve it other than using
realpath.
I also removed the preopens code and replaced it with something much
simpler. There is no longer any global state in the standard library.
Additionally-
* os.openat no longer does an unnecessary fstat on WASI when O.WRONLY
is not provided.
* os.chdir is back to causing a compile error on WASI.
Before this commit, I observe a crash from this abiSize call because the
element type is a struct that is not yet resolved. This is triggered by
running the behavior tests with -ofmt=c -target x86_64-windows.
When the bulk_memory feature is enabled, wasi-libc will only use
it if the number of bytes is >= BULK_MEMORY_THRESHOLD
Set it to 32 as in the original wasi-libc Makefile.
When a local defined outside a loop dies inside the loop, it can still
be needed on subsequent loop iterations, so reuse of the local must be
deferred until after the loop ends. This causes behavior tests to pass.
