Ambiguous spec of __wasi_fstflags_t

[marmistrz]

Possible values:

    __WASI_FILESTAT_SET_ATIM
    Adjust the last data access timestamp to the value stored in __wasi_filestat_t::st_atim.

    __WASI_FILESTAT_SET_ATIM_NOW
    Adjust the last data access timestamp to the time of clock __WASI_CLOCK_REALTIME.

    __WASI_FILESTAT_SET_MTIM
    Adjust the last data modification timestamp to the value stored in __wasi_filestat_t::st_mtim.

    __WASI_FILESTAT_SET_MTIM_NOW
    Adjust the last data modification timestamp to the time of clock __WASI_CLOCK_REALTIME.

It is unclear what the behavior is, when the both flags __WASI_FILESTAT_SET_MTIM and __WASI_FILESTAT_SET_MTIM_NOW are set. Should whichever of them take precedence or should one return EINVAL? This should be clarified in the API docs.

I suggest we return EINVAL

[kubkon]

@marmistrz are you going to file an issue in WASI issue tracker as suggested by @sunfishcode? Or @sunfishcode will you do it? Either way, after it happens, I suggest we make references from this one to the one in WASI tracker, and close this one.

[marmistrz]

I will, tomorrow.

[marmistrz]

Closing in favor of bytecodealliance/wasmtime#270