Handle ENOTCAPABLE in WASI

This commit adds `error.NotCapable` enum value and makes sure that
every applicable WASI syscall that can return `ENOTCAPABLE` errno
remaps it to `error.NotCapable.
bf8bf528c6Jakub Konka committed on 6/29/2020, 3:10:01 PMparent374e3e4
2 files changedLine totals unavailable