Following a recent change for PR 82644 the non-standard hypergeomtric
functions are not defined by <cmath> when __STRICT_ANSI__ is defined
(e.g. for -std=c++17, or -std=c++14 -D__STDCPP_WANT_MATH_SPEC_FUNCS__).
That caused errors in <tr1/cmath> because the using-declarations for
tr1::hyperg et al are invalid in strict modes.
The solution is to define the TR1 hypergeometric functions inline in
<tr1/cmath> if __STRICT_ANSI__ is defined.
PR libstdc++/82644
* include/tr1/cmath [__STRICT_ANSI__] (hypergf, hypergl, hyperg): Use
inline definitions instead of using-declarations.
[__STRICT_ANSI__] (conf_hypergf, conf_hypergl, conf_hyperg): Likewise.
* testsuite/tr1/5_numerical_facilities/special_functions/
07_conf_hyperg/compile_cxx17.cc: New.
* testsuite/tr1/5_numerical_facilities/special_functions/
17_hyperg/compile_cxx17.cc: New.
From-SVN: r259912
