Implement P0386R2 - C++17 inline variables

Implement P0386R2 - C++17 inline variables

2016-10-11  Jakub Jelinek  <jakub@redhat.com>

	* dwarf2out.c (gen_member_die): Handle inline static data member
	definitions.
c-family/
	* c-cppbuiltin.c (c_cpp_builtins): Add __cpp_inline_variables.
cp/
	* cp-tree.h (struct lang_type): Shrink language field to 1 bit
	from 4.  Add var_declared_inline_p field.  Mention 2 spare bits.
	(DECL_VAR_DECLARED_INLINE_P): Define.
	(SET_DECL_VAR_DECLARED_INLINE_P): Define.
	(DECL_INLINE_VAR_P): Define.
	(diagnose_inline_vars_for_namespace): Declare.
	* decl.c (diagnose_inline_vars_for_namespace): New function.
	(duplicate_decls): For static data members copy
	DECL_DECLARED_CONSTEXPR_P.
	(redeclaration_error_message): Handle C++17 redundant redeclaration
	of constexpr static data member outside of class.
	(maybe_commonize_var): Handle inline variables.
	(check_initializer): Ignore inline variables for diagnostics.
	Adjust diagnostic wording for C++17.
	(make_rtl_for_nonlocal_decl): Allow in-class definition of
	inline static data members.
	(bad_specifiers): Don't diagnose inline on variables here.
	(grokvardecl): Add inlinep argument, non-static const inline variables
	are TREE_PUBLIC.
	(check_static_variable_definition): Return early also for inline
	variables.
	(grokdeclarator): Handle inline variables and inline static data
	members.
	* typeck2.c (store_init_value): Don't diagnose non-constant
	initializers for non-constexpr inline static data members.
	* decl2.c (vague_linkage_p): Return true for inline variables.
	(c_parse_final_cleanups): In-class declaration of inline static
	data members is a definition.  Call diagnose_inline_vars_for_namespace
	through walk_namespaces.
	* pt.c (instantiate_decl): Set pattern_defined for in-class definitions
	of inline static data members.

From-SVN: r241137