Warnings about shadowed members

Issue description

Compiling under Linux, we get many warnings of the following form:

pybind11/detail/common.h(782): warning #1944: declaration of "v" shadows a member of 'this'
the shadowed declaration is at line 764
    any_container(std::vector<T> &&v) : v(std::move(v)) { }

pybind11/detail/common.h(782): warning #3280: declaration hides member "pybind11::detail::any_container<T>::v" (declared at line 764)
  any_container(std::vector<T> &&v) : v(std::move(v)) { }

pybind11/buffer_info.h(28): warning #1944: declaration of "ptr" shadows a member of 'this'
the shadowed declaration is at line 18
  buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,

pybind11/buffer_info.h(28): warning #3280: declaration hides member "pybind11::buffer_info::ptr" (declared at line 18)
  buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,

pybind11/buffer_info.h(28): warning #1944: declaration of "itemsize" shadows a member of 'this'
        the shadowed declaration is at line 19
  buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,

pybind11/buffer_info.h(28): warning #3280: declaration hides member "pybind11::buffer_info::itemsize" (declared at line 19)
  buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,

...and many more...

Would it be possible to get this fixed, or what is the best practice here?

Start by compiling under Linux and inspect the reported declarations in pybind11/detail/common.h and pybind11/buffer_info.h. Identify the remaining shadowed-member warnings across the affected headers, then verify that the warnings are eliminated without changing the binding behavior.