* tree.c (tree_size): For all 'c' and 'x' nodes, look directly
        at the sizes of the relevant structures, rather than relying
        on TREE_CODE_LENGTH.  Call lang_hooks.tree_size to get the
        sizes of any such we don't know about.  Use
        lang_hooks.identifier_size for IDENTIFIER_NODE.

        (initializer_zerop): Use CONSTRUCTOR_ELTS.
        * tree.def: Update commentary.  Make fourth element of
        the definition for all 'c' and 'x' nodes zero.

        * langhooks.h: New hook, tree_size / LANG_HOOKS_TREE_SIZE.
        * langhooks-def.h: Update to match.
        * langhooks.c: New default, lhd_tree_size.

        * c-common.def (SRCLOC): Kill.
        * c-pretty-print.c (pp_c_postfix_expression [case SRCLOC]):
        Remove entirely - was already #if-ed out.

ada:
        * ada-tree.def: Make fourth element for GNAT_LOOP_ID zero.
        * misc.c (gnat_tree_size): New function.
        (LANG_HOOKS_TREE_SIZE): Override.
cp:
        * cp-tree.def: Make fourth element for all 'c' and 'x' nodes zero.
        * cp-lang.c (cp_tree_size): New function.
        (LANG_HOOKS_TREE_SIZE): Override.

        * cp-tree.h (SOURCE_LOCUS, SRCLOC_FILE, SRCLOC_LINE, struct
        tree_srcloc, TS_CP_COMMON, TS_CP_SRCLOC): Kill.
        (union lang_tree_node): Remove common and srcloc members.
        (build_srcloc_here): Don't prototype.
        * decl.c (cp_tree_node_structure): Kill SRCLOC case.
        * pt.c (pending_templates): Correct comment.
        * tree.c (build_srcloc, build_srcloc_here): Kill.

From-SVN: r65323