The new constructor added for Contracts support was not explicit, so
caused ambiguities when arbitrary pointers were used in contexts which
could convert to std::source_location.
We don't actually need a constructor, the contract_violation::location()
function can just set the data member directly.
libstdc++-v3/ChangeLog:
* include/std/contracts (contract_violation::location): Use
source_location default constructor and then set _M_impl.
* include/std/source_location (source_location(const void*)):
Remove constructor.
* testsuite/18_support/contracts/includes.cc: Move to...
* testsuite/18_support/contracts/srcloc.cc: ...here. Test for
ambiguity caused by new constructor.
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
269ce3de8c