[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)

This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).

vendor/github.com/tetratelabs/wazero/experimental/sys/syscall_errno.go

@@ -0,0 +1,106 @@
+//go:build !plan9 && !aix
+
+package sys
+
+import "syscall"
+
+func syscallToErrno(err error) (Errno, bool) {
+	errno, ok := err.(syscall.Errno)
+	if !ok {
+		return 0, false
+	}
+	switch errno {
+	case 0:
+		return 0, true
+	case syscall.EACCES:
+		return EACCES, true
+	case syscall.EAGAIN:
+		return EAGAIN, true
+	case syscall.EBADF:
+		return EBADF, true
+	case syscall.EEXIST:
+		return EEXIST, true
+	case syscall.EFAULT:
+		return EFAULT, true
+	case syscall.EINTR:
+		return EINTR, true
+	case syscall.EINVAL:
+		return EINVAL, true
+	case syscall.EIO:
+		return EIO, true
+	case syscall.EISDIR:
+		return EISDIR, true
+	case syscall.ELOOP:
+		return ELOOP, true
+	case syscall.ENAMETOOLONG:
+		return ENAMETOOLONG, true
+	case syscall.ENOENT:
+		return ENOENT, true
+	case syscall.ENOSYS:
+		return ENOSYS, true
+	case syscall.ENOTDIR:
+		return ENOTDIR, true
+	case syscall.ERANGE:
+		return ERANGE, true
+	case syscall.ENOTEMPTY:
+		return ENOTEMPTY, true
+	case syscall.ENOTSOCK:
+		return ENOTSOCK, true
+	case syscall.ENOTSUP:
+		return ENOTSUP, true
+	case syscall.EPERM:
+		return EPERM, true
+	case syscall.EROFS:
+		return EROFS, true
+	default:
+		return EIO, true
+	}
+}
+
+// Unwrap is a convenience for runtime.GOOS which define syscall.Errno.
+func (e Errno) Unwrap() error {
+	switch e {
+	case 0:
+		return nil
+	case EACCES:
+		return syscall.EACCES
+	case EAGAIN:
+		return syscall.EAGAIN
+	case EBADF:
+		return syscall.EBADF
+	case EEXIST:
+		return syscall.EEXIST
+	case EFAULT:
+		return syscall.EFAULT
+	case EINTR:
+		return syscall.EINTR
+	case EINVAL:
+		return syscall.EINVAL
+	case EIO:
+		return syscall.EIO
+	case EISDIR:
+		return syscall.EISDIR
+	case ELOOP:
+		return syscall.ELOOP
+	case ENAMETOOLONG:
+		return syscall.ENAMETOOLONG
+	case ENOENT:
+		return syscall.ENOENT
+	case ENOSYS:
+		return syscall.ENOSYS
+	case ENOTDIR:
+		return syscall.ENOTDIR
+	case ENOTEMPTY:
+		return syscall.ENOTEMPTY
+	case ENOTSOCK:
+		return syscall.ENOTSOCK
+	case ENOTSUP:
+		return syscall.ENOTSUP
+	case EPERM:
+		return syscall.EPERM
+	case EROFS:
+		return syscall.EROFS
+	default:
+		return syscall.EIO
+	}
+}