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/modsupport.c	Sat Jun 09 16:13:23 2007 +0000
+++ b/Python/modsupport.c	Sun Jun 10 09:51:05 2007 +0000
@@ -65,7 +65,7 @@
 		return NULL;
 	d = PyModule_GetDict(m);
 	if (methods != NULL) {
-		n = PyString_FromString(name);
+		n = PyUnicode_FromString(name);
 		if (n == NULL)
 			return NULL;
 		for (ml = methods; ml->ml_name != NULL; ml++) {
@@ -689,5 +689,5 @@
 int 
 PyModule_AddStringConstant(PyObject *m, const char *name, const char *value)
 {
-	return PyModule_AddObject(m, name, PyString_FromString(value));
+	return PyModule_AddObject(m, name, PyUnicode_FromString(value));
 }