c++: array {}-init [PR105589]

c++: array {}-init [PR105589]

My patch for 105191 made us use build_value_init more frequently from
build_vec_init_expr, but build_value_init doesn't like to be called to
initialize a class in a template.  That's caused trouble in the past, and
seems like a strange restriction, so let's fix it.

	PR c++/105589
	PR c++/105191
	PR c++/92385

gcc/cp/ChangeLog:

	* init.cc (build_value_init): Handle class in template.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/initlist-array16.C: New test.