sandbox/seccomp: resolve rules natively

This enables loading syscall filter policies from external cross-platform config files.

This also removes a significant amount of C code.

Signed-off-by: Ophestra <cat@gensokyo.uk>

hst/template.go

@@ -57,15 +57,16 @@ func Template() *Config {
 		Groups:   []string{"video", "dialout", "plugdev"},
 
 		Container: &ContainerConfig{
-			Hostname:   "localhost",
-			Devel:      true,
-			Userns:     true,
-			Net:        true,
-			Device:     true,
-			Seccomp:    seccomp.FilterMultiarch,
-			Tty:        true,
-			Multiarch:  true,
-			MapRealUID: true,
+			Hostname:       "localhost",
+			Devel:          true,
+			Userns:         true,
+			Net:            true,
+			Device:         true,
+			SeccompFlags:   seccomp.AllowMultiarch,
+			SeccompPresets: seccomp.PresetExt,
+			Tty:            true,
+			Multiarch:      true,
+			MapRealUID:     true,
 			// example API credentials pulled from Google Chrome
 			// DO NOT USE THESE IN A REAL BROWSER
 			Env: map[string]string{