Stop returning NOTCAPABLE errors from WASI calls. (#4666)

* Stop returning `NOTCAPABLE` errors from WASI calls.

`ENOTCAPABLE` was an error code that is used as part of the rights
system, from CloudABI. There is a set of flags associated with each file
descriptor listing which operations can be performed with the file
descriptor, and if an attempt is made to perform an operation with a
file descriptor that isn't permitted by its rights flags, it fails with
`ENOTCAPABLE`.

WASI is removing the rights system. For example, WebAssembly/wasi-libc#294
removed support for translating `ENOTCAPABLE` into POSIX error codes, on
the assumption that engines should stop using it.

So as another step to migrating away from the rights system, remove uses
of the `ENOTCAPABLE` error.

* Update crates/wasi-common/src/file.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

* Update crates/wasi-common/src/dir.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

Co-authored-by: Jamey Sharp <jamey@minilop.net>

crates/test-programs/wasi-tests/src/bin/path_open_read_without_rights.rs

@@ -30,7 +30,7 @@ unsafe fn try_read_file(dir_fd: wasi::Fd) {
         wasi::fd_read(fd, &[iovec])
             .expect_err("reading bytes from file should fail")
             .raw_error(),
-        wasi::ERRNO_NOTCAPABLE
+        wasi::ERRNO_BADF
     );
 }
 

crates/test-programs/wasi-tests/src/bin/truncation_rights.rs

@@ -68,7 +68,7 @@ unsafe fn test_truncation_rights(dir_fd: wasi::Fd) {
             wasi::path_open(dir_fd, 0, "file", wasi::OFLAGS_TRUNC, 0, 0, 0)
                 .expect_err("truncating a file without path_filestat_set_size right")
                 .raw_error(),
-            wasi::ERRNO_NOTCAPABLE
+            wasi::ERRNO_PERM
         );
     }