c++: Extend build_array_type API

c++: Extend build_array_type API

The modules machinery needs to construct array types, and that wanted
to determine type dependency.  That doesn't work during loading, but
the module loader can stream that fact too and tell the array builder.
Thus this extends the API to allow a caller to specify the dependency
explicitly.  The call in cp_build_qualified_type_real is unreachable
during the loading, so that one's ok as is.

	gcc/cp/
	* cp-tree.h (build_cplus_array_type): Add defaulted DEP parm.
	* tree.c (set_array_type_common): Add DEP parm.
	(build_cplus_array_type): Add DEP parm, determine dependency if
	needed.
	(cp_build_qualified_type_real): Adjust array-building call.
	(strip_typedefs): Likewise.