Make identifiers str (not str8) objects throughout. This affects the parser, various object implementations, and all places that put identifiers into C string literals. In testing, a number of crashes occurred as code would fail when the recursion limit was reached (such as the Unicode interning dictionary having key/value pairs where key is not value). To solve these, I added an overflowed flag, which allows for 50 more recursions after the limit was reached and the exception was raised, and a recursion_critical flag, which indicates that recursion absolutely must be allowed, i.e. that a certain call must not cause a stack overflow exception. There are still some places where both str and str8 are accepted as identifiers; these should eventually be removed.

--- a/Python/pythonrun.c	Sat Jun 09 16:13:23 2007 +0000
+++ b/Python/pythonrun.c	Sun Jun 10 09:51:05 2007 +0000
@@ -1133,6 +1133,8 @@
 	PyObject *f = PySys_GetObject("stderr");
 	Py_INCREF(value);
 	if (f == NULL)
+		_PyObject_Dump(value);
+	if (f == NULL)
 		fprintf(stderr, "lost sys.stderr\n");
 	else {
 		fflush(stdout);