c++: NSDMI instantiation during overload resolution [PR110468]

Here we find ourselves instantiating the NSDMI for A<1>::m when
computing argument conversions during overload resolution, and
thus tf_conv is set.  The flag causes mark_used for the constructor
used in the NSDMI to exit early and not instantiate its noexcept-spec,
which eventually leads to an ICE from nothrow_spec_p.

This patch fixes this by clearing any special tsubst flags during
instantiation of an NSDMI, since the result should be independent of
the context that requires the instantiation.

	PR c++/110468

gcc/cp/ChangeLog:

	* init.cc (maybe_instantiate_nsdmi_init): Mask out all
	tsubst flags except for tf_warning_or_error.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/noexcept79.C: New test.

0 files changed, 0 insertions, 0 deletions