gh-114099: Modify preprocessor symbol usage to support older macOS SDKs by freakboy3742 · Pull Request #118073 · python/cpython
Older macOS SDKs don't expose the TARGET_OS_* symbols; this PR makes the preprocessor usage compatible with those older SDKs.
As discussed on PR #117887, this consolidates the two separate PRs (#117887 and #117892, both submitted by @jmroot) with an additional change to Python/marshal.c, and tags the fix against the iOS feature that introduced the issue.