Add ast.Constant

Issue #26146: Add a new kind of AST node: ast.Constant. It can be used by
external AST optimizers, but the compiler does not emit directly such node.

An optimizer can replace the following AST nodes with ast.Constant:

* ast.NameConstant: None, False, True
* ast.Num: int, float, complex
* ast.Str: str
* ast.Bytes: bytes
* ast.Tuple if items are constants too: tuple
* frozenset

Update code to accept ast.Constant instead of ast.Num and/or ast.Str:

* compiler
* docstrings
* ast.literal_eval()
* Tools/parser/unparse.py

1 files changed, 1 insertions, 0 deletions

diff --git a/Include/asdl.h b/Include/asdl.h
index 495153c..35e9fa1 100644
--- a/Include/asdl.h
+++ b/Include/asdl.h
@@ -6,6 +6,7 @@ typedef PyObject * string;
 typedef PyObject * bytes;
 typedef PyObject * object;
 typedef PyObject * singleton;
+typedef PyObject * constant;
 
 /* It would be nice if the code generated by asdl_c.py was completely
    independent of Python, but it is a goal the requires too much work