Enable LTO on macOS ARM64 (#937)

Author: ofek

setup.py

@@ -1,4 +1,5 @@
 import os
+import platform
 import sys
 
 from setuptools import setup
@@ -38,6 +39,9 @@
     extra_compile_args.extend(["-O0", "-g", "-UNDEBUG"])
 elif sys.platform != "win32":
     extra_compile_args.extend(["-g0"])
+    if sys.platform == "darwin" and platform.machine().lower() == "arm64":
+        extra_compile_args.extend(["-flto=thin"])
+        extra_link_args.extend(["-flto=thin"])
 
 # from https://py-free-threading.github.io/faq/#im-trying-to-build-a-library-on-windows-but-msvc-says-c-atomic-support-is-not-enabled
 if sys.platform == "win32":