Fix an assertion failure / accepts-invalid in -fms-extensions mode. Don't build
a dependent-scope id expression when a templated member function of a
non-templated class references an unknown identifier, since instantiation won't
rebuild it (and we can tell at parse time that it'll never work). Based on a
patch by Faisal Vali!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180701 91177308-0d34-0410-b5e6-96231b3b80d8