* doc/gnat_rm/implementation_defined_attributes.rst

* doc/gnat_rm/implementation_defined_attributes.rst
	(Scalar_Storage_Order): Adjust restriction for packed array types.
	* einfo.ads (Is_Bit_Packed_Array): Adjust description.
	(Is_Packed): Likewise.
	(Is_Packed_Array_Impl_Type): Likewise.
	(Packed_Array_Impl_Type): Likewise.
	* exp_ch4.adb (Expand_N_Indexed_Component): Do not do anything special
	if the prefix is not a packed array implemented specially.
	* exp_ch6.adb (Expand_Actuals): Expand indexed components only for
	bit-packed array types.
	* exp_pakd.adb (Install_PAT): Set Is_Packed_Array_Impl_Type flag on
	the PAT before analyzing its declaration.
	(Create_Packed_Array_Impl_Type): Remove redundant statements.
	* freeze.adb (Check_Component_Storage_Order): Reject packed array
	components only if they are bit packed.
	(Freeze_Array_Type): Fix logic detecting bit packing and do not bit
	pack for composite types whose size is multiple of a byte.
	Create the implementation type for packed array types only when it is
	needed, i.e. bit packing or packing because of holes in index types.
	Make sure the Has_Non_Standard_Rep and Is_Packed flags agree.
	* gcc-interface/gigi.h (make_packable_type): Add MAX_ALIGN parameter.
	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Signed_Integer_Subtype>:
	Call maybe_pad_type instead of building the padding type manually.
	(gnat_to_gnu_entity) <E_Array_Subtype>: Do not assert that
	Packed_Array_Impl_Type is present for packed arrays.
	(gnat_to_gnu_component_type): Also handle known alignment for packed
	types by passing it to make_packable_type.
	* gcc-interface/utils.c (make_packable_type): Add MAX_ALIGN parameter
	and deal with it in the array case.  Adjust recursive call.  Simplify
	computation of new size and cap the alignment to BIGGEST_ALIGNMENT.

From-SVN: r236279