[build] MacOS linker compat

configure.ac

@@ -1665,10 +1665,16 @@ AC_ARG_ENABLE([extra-warnings],
 
 if test "$extrawarnings" = true || test "$extrawarnings" = error; then
   TRY_CFLAGS([-g -O2 -g2 -Wall -Wmissing-declarations -Wcast-align -Wsign-compare -Wnested-externs -Wpointer-arith -D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security])
-  TRY_LDFLAGS([-Wl,--as-needed])
+  case "$host_os" in
+    *darwin* ) ;;
+    * ) TRY_LDFLAGS([-Wl,--as-needed]) ;;
+  esac
   if test "$extrawarnings" = error; then
     AS_VAR_APPEND([CFLAGS], [" -Werror"])
-    AS_VAR_APPEND([LDFLAGS], [" -Wl,--fatal-warnings"])
+    case "$host_os" in
+      *darwin* ) ;;
+      * ) AS_VAR_APPEND([LDFLAGS], [" -Wl,--fatal-warnings"]) ;;
+    esac
   fi
 fi