Fix test failures on Solaris

Add exceptions for symlinks, sticky bits, and device nodes in the same places where the BSDSs and/or Darwin have them.

cmd/restic/integration_helpers_test.go

@@ -67,7 +67,7 @@ func isSymlink(fi os.FileInfo) bool {
 
 func sameModTime(fi1, fi2 os.FileInfo) bool {
 	switch runtime.GOOS {
-	case "darwin", "freebsd", "openbsd", "netbsd":
+	case "darwin", "freebsd", "openbsd", "netbsd", "solaris":
 		if isSymlink(fi1) && isSymlink(fi2) {
 			return true
 		}