bpo-40334: PEP 617 implementation: New PEG parser for CPython (GH-19503)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 22ee596..1888335 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -816,7 +816,12 @@
     if (str == NULL)
         goto error;
 
+    int current_use_peg = PyInterpreterState_Get()->config.use_peg;
+    if (flags & PyCF_TYPE_COMMENTS || feature_version >= 0) {
+        PyInterpreterState_Get()->config.use_peg = 0;
+    }
     result = Py_CompileStringObject(str, filename, start[compile_mode], &cf, optimize);
+    PyInterpreterState_Get()->config.use_peg = current_use_peg;
     Py_XDECREF(source_copy);
     goto finally;