* c-decl.c: Verify that C_SIZEOF_STRUCT_LANG_IDENTIFIER is correct.
	(struct c_binding, struct c_scope): Add chain_next
	attributes to GTY markers.
	(struct lang_identifier, struct lang_tree_node): Define
	here...
	* c-tree.h: ... not here.  No longer need to declare struct
	c_binding either.  Do define C_SIZEOF_STRUCT_LANG_IDENTIFIER.
	* c-lang.c, objc/objc-lang.c: Set LANG_HOOKS_IDENTIFIER_SIZE
	to C_SIZEOF_STRUCT_LANG_IDENTIFIER.

	PR 14734, 11944
	* c-decl.c (get_parm_info): If error_mark_node is encountered
	in the bindings chain, unbind and discard it; don't abort.
	* testsuite/gcc.dg/noncompile/undeclared-2.c: New test.

From-SVN: r80042