* gcc-interface/trans.c (lvalue_required_for_attribute_p): New static

	function.
	(lvalue_required_p) <N_Attribute_Reference>: Call it.
	(gnat_to_gnu) <N_Selected_Component>: Prevent build_component_ref from
	folding the result only if lvalue_required_for_attribute_p is true.
	* gcc-interface/utils.c (maybe_unconstrained_array): Pass correctly
	typed constant to build_component_ref.
	(unchecked_convert): Likewise.
	* gcc-interface/utils2.c (maybe_wrap_malloc): Likewise.
	(build_allocator): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158202 138bc75d-0d04-0410-961f-82ee72b054a4