(d_pointer_to_member_type): Exit early if cplus_demangle_type returns NULL. (cplus_demangle_type): Likewise. * testsuite/demangle-expected: New testcase.
(d_pointer_to_member_type): Exit early if cplus_demangle_type returns NULL. (cplus_demangle_type): Likewise. * testsuite/demangle-expected: New testcase.