* c-decl.c (gettags, pushdecl_function_level): Delete.
(last_function_parm_vars): Rename last_function_parm_others.
(current_function_parm_vars): Rename current_function_parm_others.
(struct c_scope): Rewrite comment explaining this data structure.
Add names_last, blocks_last, parms_last fields. Rename
incomplete_list to incomplete.
(SCOPE_LIST_APPEND, SCOPE_LIST_CONCAT): New macros.
(poplevel): Ignore second argument. No need to nreverse
anything. Restructure such that each list is processed
exactly once. Use 'const location_t *locus' syntactic sugar
variable where useful. Issue unused variable warnings
ourselves, do not rely on function.c.
(insert_block, pushdecl, bind_label): Use SCOPE_LIST_APPEND.
(pushdecl_top_level): Likewise. Don't call duplicate_decls.
(implicitly_declare): decl cannot be error_mark_node.
(undeclared_variable): Manipulate scope structure directly.
(c_make_fname_decl): Likewise.
(getdecls, c_init_decl_processing): Fix comment.
(mark_forward_parm_decls): Use SCOPE_LIST_CONCAT. No need
for 'last' variable.
(grokparms): No need to nreverse parms list.
(store_parm_decls_newstyle): Set up the parms_last and
names_last fields of the new scope too.
(store_parm_decls_oldstyle): Can assume DECL_WEAK is not set
on parms to begin with; check this under ENABLE_CHECKING. Set
up parms_last.
(check_for_loop_decls): Refer directly to current_scope->tags.
Use consistent quote style in diagnostics.
(c_write_global_declarations): The names list is not backward.
* c-common.h: Don't prototype gettags.
* c-parse.in: Call poplevel with second argument 0 always.