+extern tree c_common_type_for_mode PARAMS ((enum machine_mode,
+ int));
+extern tree c_common_type_for_size PARAMS ((unsigned int, int));
+extern tree c_common_unsigned_type PARAMS ((tree));
+extern tree c_common_signed_type PARAMS ((tree));
+extern tree c_common_signed_or_unsigned_type PARAMS ((int, tree));
+extern tree c_common_truthvalue_conversion PARAMS ((tree));