Merge pull request #2325 in HDFFV/hdf5 from ~DYOUNG/werror:h5t_copy to develop
Merged per discussion with Elena.
* commit '3f903a441ad84001ea66589728bd8b036b6fdfca':
Take out the temporary performance tests.
Make calls through a function pointer. Use the same number of arguments, always.
Increase iterations, provide a baseline for no-op, simplify the overhead case a bit.
Temporarily add some code that measures the time to run the simplest possible H5T__copy_all()-like routine 10 million times and then measures the version with FUNC_ENTER_STATIC/_LEAVE_NOAPI and a HGOTO_ERROR() statement.
H5T_copy() constification plus Quincey's contributions.