_PyUnicode_IsWhitespace(),

_PyUnicode_IsLinebreak():
Changed the declarations to match the definitions.

Don't know why they differed; MSVC warned about it;
don't know why only these two functions use "const".
Someone who does may want to do something saner ;-).

Include/unicodeobject.h

@@ -1152,11 +1152,11 @@ PyAPI_FUNC(int) _PyUnicode_IsTitlecase(
     );
 
 PyAPI_FUNC(int) _PyUnicode_IsWhitespace(
-    Py_UNICODE ch 	/* Unicode character */
+    const Py_UNICODE ch 	/* Unicode character */
     );
 
 PyAPI_FUNC(int) _PyUnicode_IsLinebreak(
-    Py_UNICODE ch 	/* Unicode character */
+    const Py_UNICODE ch 	/* Unicode character */
     );
 
 PyAPI_FUNC(Py_UNICODE) _PyUnicode_ToLowercase(