ninja&make/mac: Only pass -x for loadable_modules.

test/mac/strip/file.c

Index: test/mac/strip/file.c
===================================================================
--- test/mac/strip/file.c	(revision 1721)
+++ test/mac/strip/file.c	(working copy)
@@ -3,7 +3,16 @@
 // found in the LICENSE file.
 
 static void the_static_function() {}
+__attribute__((used)) void the_used_function() {}
 
+__attribute__((visibility("hidden"))) __attribute__((used))
+void the_hidden_function() {}
+__attribute__((visibility("default"))) __attribute__((used))
+void the_visible_function() {}
+
 void the_function() {
   the_static_function();
+  the_used_function();
+  the_hidden_function();
+  the_visible_function();
 }