Recognize macOS 11 and later.
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=44605
--- configure.orig	2022-01-26 03:06:46.000000000 -0600
+++ configure	2022-01-26 03:07:54.000000000 -0600
@@ -8039,7 +8039,7 @@
              10.[012])
                allow_undefined_flag='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
                ;;
-             10.*)
+             *)
                allow_undefined_flag='${wl}-undefined ${wl}dynamic_lookup'
                ;;
            esac
@@ -11102,7 +11102,7 @@
              10.[012])
                allow_undefined_flag_CXX='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
                ;;
-             10.*)
+             *)
                allow_undefined_flag_CXX='${wl}-undefined ${wl}dynamic_lookup'
                ;;
            esac
@@ -14615,7 +14615,7 @@
              10.[012])
                allow_undefined_flag_F77='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
                ;;
-             10.*)
+             *)
                allow_undefined_flag_F77='${wl}-undefined ${wl}dynamic_lookup'
                ;;
            esac
@@ -17242,7 +17242,7 @@
              10.[012])
                allow_undefined_flag_GCJ='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
                ;;
-             10.*)
+             *)
                allow_undefined_flag_GCJ='${wl}-undefined ${wl}dynamic_lookup'
                ;;
            esac