Issue 40000: Improve AST validation for Constant nodes

When something that isn't constant found in a ast.Constant node's body, python reports errors like this

>>> e = ast.Expression(body=ast.Constant(value=type))
>>> ast.fix_missing_locations(e)
<_ast.Expression object at 0x7fc2c23981c0>
>>> compile(e, "<test>", "eval")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: got an invalid type in Constant: type

But if something is part of constant tuple and frozenset isn't constant, the error reporting is wrong 

>>> e = ast.Expression(body=ast.Constant(value=(1,2,type)))
>>> compile(e, "<test>", "eval")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: got an invalid type in Constant: tuple

This should've been 

TypeError: got an invalid type in Constant: type

You got an anniversary issue!

Congratulations Batuhan! You win with the bug number 40000! A nice number ;-) To be honest, I wanted to get it, but I didn't want to cheat by opening a stupid issue.

sorry to take it Victor, maybe you can get the perfect issue number when we migrate to github?

New changeset 0ac59f93c0e3f91fd994d7245578cce65654fb22 by Batuhan Taşkaya in branch 'master':
bpo-40000: Improve error messages when validating invalid ast.Constant nodes (GH-19055)
https://github.com/python/cpython/commit/0ac59f93c0e3f91fd994d7245578cce65654fb22

> _PyType_Name(Py_TYPE(value)))

Why truncating the type name in the error message? The qualified name (don't call _PyType_Name()) should provide more information, no?