Patches Mongo's third party copy of gperftools libc_override_osx.h for Sierra

mongodb-2.4.14-gperftools-2.0-libc_override_osx.h.patch

diff --git a/src/third_party/gperftools-2.0/src/libc_override_osx.h b/src/third_party/gperftools-2.0/src/libc_override_osx.h
index 78a0ef2f95..13ec5b8d66 100644
--- a/src/third_party/gperftools-2.0/src/libc_override_osx.h
+++ b/src/third_party/gperftools-2.0/src/libc_override_osx.h
@@ -205,6 +205,33 @@ extern "C" {
   size_t malloc_usable_size(void* p)     { return tc_malloc_size(p); }
 }  // extern "C"
 
+static malloc_zone_t *get_default_zone()
+{
+	malloc_zone_t **zones = NULL;
+	unsigned int num_zones = 0;
+
+	/*
+	 * On OSX 10.12, malloc_default_zone returns a special zone that is not
+	 * present in the list of registered zones. That zone uses a "lite zone"
+	 * if one is present (apparently enabled when malloc stack logging is
+	 * enabled), or the first registered zone otherwise. In practice this
+	 * means unless malloc stack logging is enabled, the first registered
+	 * zone is the default.
+	 * So get the list of zones to get the first one, instead of relying on
+	 * malloc_default_zone.
+	 */
+        if (KERN_SUCCESS != malloc_get_all_zones(0, NULL, (vm_address_t**) &zones,
+	                                         &num_zones)) {
+		/* Reset the value in case the failure happened after it was set. */
+		num_zones = 0;
+	}
+
+	if (num_zones)
+		return zones[0];
+
+	return malloc_default_zone();
+}
+
 static void ReplaceSystemAlloc() {
   static malloc_introspection_t tcmalloc_introspection;
   memset(&tcmalloc_introspection, 0, sizeof(tcmalloc_introspection));
@@ -267,7 +294,7 @@ static void ReplaceSystemAlloc() {
   // zone.  The default zone is then re-registered to ensure that
   // allocations made from it earlier will be handled correctly.
   // Things are not guaranteed to work that way, but it's how they work now.
-  malloc_zone_t *default_zone = malloc_default_zone();
+  malloc_zone_t *default_zone = get_default_zone();
   malloc_zone_unregister(default_zone);
   malloc_zone_register(default_zone);
 }

Cribbed the code for get_default_zone from jemalloc/jemalloc#427