[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/internal/sysfs/dir.go

@@ -0,0 +1,24 @@
+package sysfs
+
+import (
+	"io"
+
+	"github.com/tetratelabs/wazero/experimental/sys"
+)
+
+func adjustReaddirErr(f sys.File, isClosed bool, err error) sys.Errno {
+	if err == io.EOF {
+		return 0 // e.g. Readdir on darwin returns io.EOF, but linux doesn't.
+	} else if errno := sys.UnwrapOSError(err); errno != 0 {
+		errno = dirError(f, isClosed, errno)
+		// Comply with errors allowed on sys.File Readdir
+		switch errno {
+		case sys.EINVAL: // os.File Readdir can return this
+			return sys.EBADF
+		case sys.ENOTDIR: // dirError can return this
+			return sys.EBADF
+		}
+		return errno
+	}
+	return 0
+}