gh-113299: Move cpp.py into libclinic (#113526)

Lib/test/test_clinic.py

@@ -3920,7 +3920,7 @@ class ClinicReprTests(unittest.TestCase):
         self.assertEqual(repr(parameter), "<clinic.Parameter 'bar'>")
 
     def test_Monitor_repr(self):
-        monitor = clinic.cpp.Monitor("test.c")
+        monitor = libclinic.cpp.Monitor("test.c")
         self.assertRegex(repr(monitor), r"<clinic.Monitor \d+ line=0 condition=''>")
 
         monitor.line_number = 42

Tools/clinic/clinic.py

@@ -13,7 +13,6 @@ import builtins as bltns
 import collections
 import contextlib
 import copy
-import cpp
 import dataclasses as dc
 import enum
 import functools
@@ -53,6 +52,7 @@ from typing import (
 
 # Local imports.
 import libclinic
+import libclinic.cpp
 from libclinic import ClinicError
 
 
@@ -648,7 +648,7 @@ class CLanguage(Language):
 
     def __init__(self, filename: str) -> None:
         super().__init__(filename)
-        self.cpp = cpp.Monitor(filename)
+        self.cpp = libclinic.cpp.Monitor(filename)
 
     def parse_line(self, line: str) -> None:
         self.cpp.writeline(line)

Tools/clinic/libclinic/cpp.py

@@ -3,7 +3,10 @@ import re
 import sys
 from typing import NoReturn
 
-from libclinic.errors import ParseError
+from .errors import ParseError
+
+
+__all__ = ["Monitor"]
 
 
 TokenAndCondition = tuple[str, str]