Uniquization of constants at the Tree level

	Uniquization of constants at the Tree level
	* tree.h (DECL_IN_CONSTANT_POOL): New macro
	(tree_decl_with_vis): Add in_constant_pool bit, move shadowed_for_var_p
	bit to the end.
	(tree_output_constant_def): Declare.
	* gimplify.c (gimplify_init_constructor): When using block copy,
	uniquize the constant constructor on the RHS.
	* lto-streamer-in.c (unpack_ts_decl_with_vis_value_fields): Deal
	with DECL_IN_CONSTANT_POOL flag.
	* lto-streamer-out.c (pack_ts_decl_with_vis_value_fields): Likewise.
	* varasm.c (make_decl_rtl): Deal with variables belonging to the
	global constant pool.
	(assemble_variable): Deal with symbols belonging to the tree constant
	pool.
	(get_constant_section): Add ALIGN parameter and simplify.
	(build_constant_desc): Build a VAR_DECL and attach it to the symbol.
	(assemble_constant_contents): Use the expression of the VAR_DECL.
	(output_constant_def_contents): Use the alignment of the VAR_DECL.
	(tree_output_constant_def): New global function.
	(mark_constant): Use the expression of the VAR_DECL.
	(place_block_symbol): Use the alignment of the VAR_DECL and the size
	of its expression.
	(output_object_block): Likewise and assemble the expression.
ada/
	* gcc-interface/trans.c (gnat_gimplify_expr) <ADDR_EXPR>: Uniquize
	constant constructors before taking their address.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158838 138bc75d-0d04-0410-961f-82ee72b054a4