re PR middle-end/6392 (Problems with __restrict__ type qualifier (array))
PR c++/6392
* cp/tree.c (build_cplus_array_type): Handle all quals the same.
(cp_build_qualified_type_real): Look through arrays first.
* c-common.c (c_build_qualified_type): Look through arrays first.
(c_apply_type_quals_to_decl): Look through arrays.
* c-common.c (c_apply_type_quals_to_decl): Unset TREE_READONLY for
types with constructors.