c++: non-dep array list-init w/ non-triv dtor [PR109899]

c++: non-dep array list-init w/ non-triv dtor [PR109899]

The get_target_expr call added in r12-7069-g119cea98f66476 causes us
for the below testcase to call build_vec_delete in a template context,
which builds a templated destructor call and checks expr_noexcept_p for
it, which ICEs because the call has templated form.

Much of the work of build_vec_delete however is code generation and thus
will just get discarded in a template context, and that includes the
code guarded by expr_noexcept_p.  So this patch narrowly fixes this ICE
by eliding the expr_noexcept_p call when in a template context.

	PR c++/109899

gcc/cp/ChangeLog:

	* init.cc (build_vec_delete_1): Assume expr_noexcept_p returns
	false in a template context.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/initlist-array21.C: New test.

Reviewed-by: Jason Merrill <jason@redhat.com>