[Test] Embedded: Add lit.local.cfg.

Pick up the version committed on main.

Author: nate-chandler

test/embedded/lit.local.cfg

@@ -0,0 +1,12 @@
+# Make a local copy of the substitutions.
+config.substitutions = list(config.substitutions)
+
+if config.target_sdk_name == 'macosx':
+  def do_fixup(key, value):
+    if isinstance(value, str):
+      value = value.replace("-apple-macosx10.13", "-apple-macos14")
+    elif isinstance(value, SubstituteCaptures):
+      value.substitution = value.substitution.replace("-apple-macosx10.13", "-apple-macos14")
+    return (key, value)
+
+  config.substitutions = [do_fixup(a, b) for (a, b) in config.substitutions]