Add ":macos" alias for ":osx" platform constraint.

PiperOrigin-RevId: 265457506
Change-Id: Ia01ccb0e598126c24b25b9eb9358d587d5430e7a
diff --git a/os/BUILD b/os/BUILD
index 2b3aeda..aefa0ee 100644
--- a/os/BUILD
+++ b/os/BUILD
@@ -52,6 +52,11 @@
     constraint_setting = ":os",
 )
 
+alias(
+    name = "macos",
+    actual = ":osx",
+)
+
 constraint_value(
     name = "tvos",
     constraint_setting = ":os",