* gdbtypes.h (struct language_defn): Add forward declaration.
(lookup_typename): Add LANGUAGE and GDBARCH parameters.
(lookup_unsigned_typename): Likewise.
(lookup_signed_typename): Likewise.
* gdbtypes.c (lookup_typename): Add LANGUAGE and GDBARCH parameters.
Use them instead of current_language and current_gdbarch.
(lookup_unsigned_typename): Add LANGUAGE and GDBARCH parameters.
Pass them to lookup_typename.
(lookup_signed_typename): Likewise.
* c-exp.y: Pass parse_language and parse_gdbarch to
lookup_unsigned_typename and lookup_signed_typename.
* objc-exp.y: Likewise.
* m2-exp.y: Pass parse_language and parse_gdbarch to lookup_typename.
* c-lang.c (evaluate_subexp_c): Pass expression language and
gdbarch to lookup_typename.
* printcmd.c (printf_command): Pass current language and
gdbarch to lookup_typename.
* python/python-type.c (typy_lookup_typename): Likewise.
Include "language.h".