gh-102856: Python tokenizer implementation for PEP 701 (#104323)

This commit replaces the Python implementation of the tokenize module with an implementation
that reuses the real C tokenizer via a private extension module. The tokenize module now implements
a compatibility layer that transforms tokens from the C tokenizer into Python tokenize tokens for backward
compatibility.

As the C tokenizer does not emit some tokens that the Python tokenizer provides (such as comments and non-semantic newlines), a new special mode has been added to the C tokenizer mode that currently is only used via
the extension module that exposes it to the Python layer. This new mode forces the C tokenizer to emit these new extra tokens and add the appropriate metadata that is needed to match the old Python implementation.

Co-authored-by: Pablo Galindo <pablogsal@gmail.com>

Include/internal/pycore_global_objects_fini_generated.h

@@ -918,6 +918,7 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) {
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(exception));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(exp));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(extend));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(extra_tokens));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(facility));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(factory));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(false));

Include/internal/pycore_global_strings.h

@@ -406,6 +406,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(exception)
         STRUCT_FOR_ID(exp)
         STRUCT_FOR_ID(extend)
+        STRUCT_FOR_ID(extra_tokens)
         STRUCT_FOR_ID(facility)
         STRUCT_FOR_ID(factory)
         STRUCT_FOR_ID(false)

Include/internal/pycore_runtime_init_generated.h

@@ -912,6 +912,7 @@ extern "C" {
     INIT_ID(exception), \
     INIT_ID(exp), \
     INIT_ID(extend), \
+    INIT_ID(extra_tokens), \
     INIT_ID(facility), \
     INIT_ID(factory), \
     INIT_ID(false), \

Include/internal/pycore_token.h

@@ -77,7 +77,9 @@ extern "C" {
 #define FSTRING_START   61
 #define FSTRING_MIDDLE  62
 #define FSTRING_END     63
-#define ERRORTOKEN      64
+#define COMMENT         64
+#define NL              65
+#define ERRORTOKEN      66
 #define N_TOKENS        68
 #define NT_OFFSET       256
 

Include/internal/pycore_unicodeobject_generated.h

@@ -1059,6 +1059,9 @@ _PyUnicode_InitStaticStrings(PyInterpreterState *interp) {
     string = &_Py_ID(extend);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);
+    string = &_Py_ID(extra_tokens);
+    assert(_PyUnicode_CheckConsistency(string, 1));
+    _PyUnicode_InternInPlace(interp, &string);
     string = &_Py_ID(facility);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);