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/Objects/funcobject.c	Sat Jun 09 16:13:23 2007 +0000
+++ b/Objects/funcobject.c	Sun Jun 10 09:51:05 2007 +0000
@@ -322,7 +322,7 @@
 
 	/* Not legal to del f.func_name or to set it to anything
 	 * other than a string object. */
-	if (value == NULL || !PyString_Check(value)) {
+	if (value == NULL || (!PyString_Check(value) && !PyUnicode_Check(value))) {
 		PyErr_SetString(PyExc_TypeError,
 				"__name__ must be set to a string object");
 		return -1;
@@ -516,7 +516,7 @@
 	if (nfree != nclosure)
 		return PyErr_Format(PyExc_ValueError,
 				    "%s requires closure of length %zd, not %zd",
-				    PyString_AS_STRING(code->co_name),
+				    PyUnicode_AsString(code->co_name),
 				    nfree, nclosure);
 	if (nclosure) {
 		Py_ssize_t i;