PR 1860 makes following files be generated from token.py:

* Include/token.h
* Parser/token.c. New file containing the array of token names _PyParser_TokenNames, and functions PyToken_OneChar(), PyToken_TwoChars(), PyToken_ThreeChars(), moved from Parser/tokenizer.c.
* Doc/library/token-list.inc. New file containing the list of token.py constants, it is included in Doc/library/token.rst.

New Makefile target regen-token regenerates these files.

The dict EXACT_TOKEN_TYPES that maps operator strings to token names now is automatically generated and moved from tokenize.py to token.py. Tokens COMMENT, NL and ENCODING used only in tokenize.py now are added in token.py as in issue25324.