add features flag

Author: rickeylev

python/features.bzl

@@ -31,6 +31,14 @@ def _features_typedef():
     :::
     ::::
 
+    ::::{field} py_info_site_packages_symlinks
+
+    True if the `PyInfo.site_packages_symlinks` field is available.
+
+    :::{versionadded} VERSION_NEXT_FEATURE
+    :::
+    ::::
+
     ::::{field} uses_builtin_rules
     :type: bool
 
@@ -51,7 +59,9 @@ def _features_typedef():
 
 features = struct(
     TYPEDEF = _features_typedef,
+    # keep sorted
     precompile = True,
+    py_info_site_packages_symlinks = True,
     uses_builtin_rules = not config.enable_pystar,
     version = _VERSION_PRIVATE if "$Format" not in _VERSION_PRIVATE else "",
 )