go/internal/gccgoimporter: recognize aixbigafMagic archives

Change-Id: Ice7ec681628ad7ec5ccae45f70e76fc350e9f7e6
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/255201
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Cherry Zhang <cherryyz@google.com>
diff --git a/libgo/go/go/internal/gccgoimporter/importer.go b/libgo/go/go/internal/gccgoimporter/importer.go
index ff484a7..391477d 100644
--- a/libgo/go/go/internal/gccgoimporter/importer.go
+++ b/libgo/go/go/internal/gccgoimporter/importer.go
@@ -198,7 +198,7 @@
 			return
 		}
 
-		if magics == archiveMagic {
+		if magics == archiveMagic || magics == aixbigafMagic {
 			reader, err = arExportData(reader)
 			if err != nil {
 				return