[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/sock/sock.go

@@ -0,0 +1,89 @@
+package sock
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/tetratelabs/wazero/experimental/sys"
+)
+
+// TCPSock is a pseudo-file representing a TCP socket.
+type TCPSock interface {
+	sys.File
+
+	Accept() (TCPConn, sys.Errno)
+}
+
+// TCPConn is a pseudo-file representing a TCP connection.
+type TCPConn interface {
+	sys.File
+
+	// Recvfrom only supports the flag sysfs.MSG_PEEK
+	// TODO: document this like sys.File with known sys.Errno
+	Recvfrom(p []byte, flags int) (n int, errno sys.Errno)
+
+	// TODO: document this like sys.File with known sys.Errno
+	Shutdown(how int) sys.Errno
+}
+
+// ConfigKey is a context.Context Value key. Its associated value should be a Config.
+type ConfigKey struct{}
+
+// Config is an internal struct meant to implement
+// the interface in experimental/sock/Config.
+type Config struct {
+	// TCPAddresses is a slice of the configured host:port pairs.
+	TCPAddresses []TCPAddress
+}
+
+// TCPAddress is a host:port pair to pre-open.
+type TCPAddress struct {
+	// Host is the host name for this listener.
+	Host string
+	// Port is the port number for this listener.
+	Port int
+}
+
+// WithTCPListener implements the method of the same name in experimental/sock/Config.
+//
+// However, to avoid cyclic dependencies, this is returning the *Config in this scope.
+// The interface is implemented in experimental/sock/Config via delegation.
+func (c *Config) WithTCPListener(host string, port int) *Config {
+	ret := c.clone()
+	ret.TCPAddresses = append(ret.TCPAddresses, TCPAddress{host, port})
+	return &ret
+}
+
+// Makes a deep copy of this sockConfig.
+func (c *Config) clone() Config {
+	ret := *c
+	ret.TCPAddresses = make([]TCPAddress, 0, len(c.TCPAddresses))
+	ret.TCPAddresses = append(ret.TCPAddresses, c.TCPAddresses...)
+	return ret
+}
+
+// BuildTCPListeners build listeners from the current configuration.
+func (c *Config) BuildTCPListeners() (tcpListeners []*net.TCPListener, err error) {
+	for _, tcpAddr := range c.TCPAddresses {
+		var ln net.Listener
+		ln, err = net.Listen("tcp", tcpAddr.String())
+		if err != nil {
+			break
+		}
+		if tcpln, ok := ln.(*net.TCPListener); ok {
+			tcpListeners = append(tcpListeners, tcpln)
+		}
+	}
+	if err != nil {
+		// An error occurred, cleanup.
+		for _, l := range tcpListeners {
+			_ = l.Close() // Ignore errors, we are already cleaning.
+		}
+		tcpListeners = nil
+	}
+	return
+}
+
+func (t TCPAddress) String() string {
+	return fmt.Sprintf("%s:%d", t.Host, t.Port)
+}