sync with a more appropriate version of the definitions.
as we use the "wasi_ephemeral_nn", which is p1-based, it seems
more appropriate to use definitions from witx, not wit.
it's a bit unfortunate p2-based wasi-nn made gratuitous changes
like this from p1.
note: this is an ABI change.
- All files under *core/iwasm/libraries/wasi-nn* are compiled as shared libraries
- *wasi-nn.c* is shared between backends
- Every backend has a separated shared library
- If wasi-nn feature is enabled, iwasm will depend on shared library libiwasm.so
instead of linking static library libvmlib.a
Major changes:
- Public headers inside `wasi-nn/include`
- Put cmake files in `cmake` folder
- Make linux iwasm link with `${WASI_NN_LIBS}` so iwasm can enable wasi-nn
