Replace boost::is_member_pointer with std::is_member_pointer (#1085)
Replace boost::is_member_pointer with std::is_member_pointer (#1085)

Summary:
:
- Replace a call site in `DynamicParser-inl.h` using `boost::is_member_pointer`
  with the standard library equivalent.
Pull Request resolved: https://github.com/facebook/folly/pull/1085

Reviewed By: meyering

Differential Revision: D14638847

Pulled By: yfeldblum

fbshipit-source-id: 8eb95607dc7134b9bbc6974052094a92623fe776

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly