libgo: recognize aarch64_be as arm64be

Fixes https://gcc.gnu.org/PR92810

Change-Id: I8584cb278cd0c8f2ee69922901730601121a280a
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/210038
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/libgo/configure b/libgo/configure
index ba80569..6a65a60 100755
--- a/libgo/configure
+++ b/libgo/configure
@@ -14056,6 +14056,9 @@
   aarch64-*-*)
     GOARCH=arm64
     ;;
+  aarch64_be-*-*)
+    GOARCH=arm64be
+    ;;
   arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
     GOARCH=arm
     case ${host} in
diff --git a/libgo/configure.ac b/libgo/configure.ac
index 00b4054..d4ee59c 100644
--- a/libgo/configure.ac
+++ b/libgo/configure.ac
@@ -240,6 +240,9 @@
   aarch64-*-*)
     GOARCH=arm64
     ;;
+  aarch64_be-*-*)
+    GOARCH=arm64be
+    ;;
   arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
     GOARCH=arm
     case ${host} in