In test_cext: Tell setuptools when we are generating a limited_api module

Author: stefanor

Lib/test/test_cext/setup.py

@@ -107,6 +107,8 @@ def main():
     if internal:
         cflags.append('-DTEST_INTERNAL_C_API=1')
 
+    py_limited_api = limited or abi3t
+
     # Add additional include and library directories, typically for in-tree
     # testing where not all directories are inferred
     include_dirs = []
@@ -131,7 +133,9 @@ def main():
         sources=sources,
         extra_compile_args=cflags,
         include_dirs=include_dirs,
-        library_dirs=library_dirs)
+        library_dirs=library_dirs,
+        py_limited_api=py_limited_api
+    )
     setup(name=f'internal_{module_name}',
           version='0.0',
           ext_modules=[ext])