Implement PEP 3131. Add isidentifier to str.
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 54b7129..5545344 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -182,6 +182,7 @@
 # define PyUnicode_GetDefaultEncoding PyUnicodeUCS2_GetDefaultEncoding
 # define PyUnicode_GetMax PyUnicodeUCS2_GetMax
 # define PyUnicode_GetSize PyUnicodeUCS2_GetSize
+# define PyUnicode_IsIdentifier PyUnicodeUCS2_IsIdentifier
 # define PyUnicode_Join PyUnicodeUCS2_Join
 # define PyUnicode_Partition PyUnicodeUCS2_Partition
 # define PyUnicode_RPartition PyUnicodeUCS2_RPartition
@@ -268,6 +269,7 @@
 # define PyUnicode_GetDefaultEncoding PyUnicodeUCS4_GetDefaultEncoding
 # define PyUnicode_GetMax PyUnicodeUCS4_GetMax
 # define PyUnicode_GetSize PyUnicodeUCS4_GetSize
+# define PyUnicode_IsIdentifier PyUnicodeUCS4_IsIdentifier
 # define PyUnicode_Join PyUnicodeUCS4_Join
 # define PyUnicode_Partition PyUnicodeUCS4_Partition
 # define PyUnicode_RPartition PyUnicodeUCS4_RPartition
@@ -1250,6 +1252,10 @@
     PyObject *element		/* Element string */
     );
 
+/* Checks whether argument is a valid identifier. */
+
+PyAPI_FUNC(int) PyUnicode_IsIdentifier(PyObject *s);
+
 /* Externally visible for str.strip(unicode) */
 PyAPI_FUNC(PyObject *) _PyUnicode_XStrip(
     PyUnicodeObject *self,