Implement P0035R4, C++17 new of over-aligned types.

Implement P0035R4, C++17 new of over-aligned types.

gcc/cp/
	* cp-tree.h (enum cp_tree_index): Add CPTI_ALIGN_TYPE.
	(align_type_node): New macro.
	* call.c (build_operator_new_call): Handle C++17 aligned new.
	(second_parm_is_size_t, build_op_delete_call): Likewise.
	(non_placement_deallocation_fn_p): Likewise. Rename to
	usual_deallocation_fn_p.
	(aligned_allocation_fn_p, aligned_deallocation_fn_p): New.
	* decl.c (cxx_init_decl_processing): Add aligned new support.
	* init.c (type_has_new_extended_alignment): New.
	(build_new_1): Handle aligned new.
	* tree.c (vec_copy_and_insert): New.
gcc/c-family/
	* c.opt: Add -faligned-new and -Waligned-new.
	* c-common.c (max_align_t_align): Split out from...
	(cxx_fundamental_alignment_p): ...here.
	* c-common.h: Declare it.
	* c-cppbuiltin.c (c_cpp_builtins): Handle aligned new.
libstdc++-v3/
	* libsupc++/new: Declare aligned new/delete operators.
	* config/abi/pre/gnu.ver: Export them.
	* configure.ac: Check for aligned_alloc, posix_memalign, memalign,
	_aligned_malloc.
	* libsupc++/new_opa.cc: New.
	* libsupc++/new_opant.cc: New.
	* libsupc++/new_opva.cc: New.
	* libsupc++/new_opva.cc: New.
	* libsupc++/del_opa.cc: New.
	* libsupc++/del_opant.cc: New.
	* libsupc++/del_opsa.cc: New.
	* libsupc++/del_opva.cc: New.
	* libsupc++/del_opvant.cc: New.
	* libsupc++/del_opvsa.cc: New.
	* libsupc++/Makefile.am: Build them.

From-SVN: r240056