This will help address libstdc++/65840:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65840

gdb/ChangeLog:

2015-04-27  Siva Chandra Reddy  <sivachandra@google.com>

        * NEWS (Python Scripting): Mention the new gdb.Value methods.
        * python/py-value.c (valpy_reference_value): New function.
        (valpy_const_value): Likewise.
        (value_object_methods): Add new methods.
        * value.c (make_cv_value): New function.
        * value.h (make_cv_value): Declare.

gdb/doc/ChangeLog:

2015-04-27  Siva Chandra Reddy  <sivachandra@google.com>

        * python.texi (Values From Inferior): Add descriptions of new
        methods gdb.Value.reference_value and gdb.Value.const_value.

gdb/testsuite/ChangeLog:

2015-04-27  Siva Chandra Reddy  <sivachandra@google.com>

        * gdb.python/py-xmethods.cc: Enhance test case.
        * gdb.python/py-xmethods.exp: New tests.
        * gdb.python/py-xmethods.py (A_indexoper): New xmethod worker
        function.
        (B_indexoper): Likewise.
        (global_dm_list) : Add new xmethod worker functions.