* wasi-common: remove allocate from WasiFile trait, always fail with NOTSUP
This operation from cloudabi is linux-specific, isn't even
supported across all linux filesystems, and has no support on macos
or windows. Rather than ship spotty support, it has been removed
from preview 2, and we are no longer supporting it in preview 1 as
well.
The preview 1 implementation will still check if fd is a file, and has
rights, just to reject those cases with the errors expected.
* wasi-tests: expect fd_allocate to always fail now.
rewrite the file_allocate test to just check for failure.
remove use of fd_allocate from fd_advise test, and remove test
configuration setting used for excluding use of fd_allocate on macos and
windows.
