pythongh-153568: Reduce parser allocations (python#157374)

Author: pablogsal

Grammar/python.gram

@@ -1181,8 +1181,12 @@ invalid_arguments:
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
     | a=args ',' args { _PyPegen_arguments_parsing_error(p, a) }
 invalid_kwarg:
-    | a[Token*]=('True'|'False'|'None') b='=' {
-        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to %s", PyBytes_AS_STRING(a->bytes)) }
+    | a='True' b='=' {
+        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to True") }
+    | a='False' b='=' {
+        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to False") }
+    | a='None' b='=' {
+        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to None") }
     | a=NAME b='=' expression for_if_clauses {
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
     | !(NAME '=') a=expression b='=' {

Misc/NEWS.d/next/Core_and_Builtins/2026-09-12-12-00-00.gh-issue-153568.parser.rst

@@ -0,0 +1 @@
+Reduce temporary allocations while parsing Python source.