basic_string.h doesn't define the non-w string version of std::stold
when certain conditions aren't met, and then a couple of tests fail to
compile.
Guard the portions of the tests that depend on std::stold with the
conditions for it to be defined.
for libstdc++-v3/ChangeLog
* testsuite/21_strings/basic_string/numeric_conversions/char/stold.cc:
Guard non-wide stold calls with conditions for it to be
defined.
* testsuite/27_io/basic_ostream/inserters_arithmetic/char/hexfloat.cc:
Likewise.
207534061f