re PR go/92810 (Compiling GCC go for aarch64_be-marvell-linux-gnu fails)

	PR go/92810
    libgo: recognize aarch64_be as arm64be
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/210038

From-SVN: r279032

gcc/go/gofrontend/MERGE

-a59794347b9db6dc2101a65c3e1a068051c0ee81
+e32651d37e0c43bb7595ac94363b079610bed746
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/configure

@@ -14056,6 +14056,9 @@ case ${host} in
   aarch64-*-*)
     GOARCH=arm64
     ;;
+  aarch64_be-*-*)
+    GOARCH=arm64be
+    ;;
   arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
     GOARCH=arm
     case ${host} in

libgo/configure.ac

@@ -240,6 +240,9 @@ case ${host} in
   aarch64-*-*)
     GOARCH=arm64
     ;;
+  aarch64_be-*-*)
+    GOARCH=arm64be
+    ;;
   arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
     GOARCH=arm
     case ${host} in