c++: dependent and non-dependent attributes [PR104245]

c++: dependent and non-dependent attributes [PR104245]

A flaw in my patch for PR51344 was that cplus_decl_attributes calls
decl_attributes after save_template_attributes, which messes up the ordering
that save_template_attributes set up.  Fixed by splitting
save_template_attributes around the call to decl_attributes.

	PR c++/104245
	PR c++/51344

gcc/cp/ChangeLog:

	* decl2.cc (save_template_attributes): Take late attrs as parm.
	(cplus_decl_attributes): Call it after decl_attributes,
	splice_template_attributes before.

gcc/testsuite/ChangeLog:

	* g++.dg/lto/alignas1_0.C: New test.