c++: operator new lookup [PR98249]

c++: operator new lookup [PR98249]

The standard says, as we quote in the comment just above, that if we don't
find operator new in the allocated type, it should be looked up in the
global scope.  This is specifically ::, not just any namespace, and we
already give an error for an operator new declared in any other namespace.

	PR c++/98249

gcc/cp/ChangeLog:

	* call.cc (build_operator_new_call): Just look in ::.

gcc/testsuite/ChangeLog:

	* g++.dg/lookup/new3.C: New test.