* ada-lang.c (assign_component): Use platform-specific integer type
instead of builtin_type_int32 type.
(ada_evaluate_subexp) [OP_ATR_SIZE]: Likewise.
* ax-gdb.c (gen_expr) [UNOP_NEG]: Use platform-specific integer type
instead of builtin_type_int8 type.
* valarith.c (value_x_unop): Likewise.
* python/python-value.c (valpy_absolute): Avoid reference to
builtin_type_int8 type.
* eval.c (evaluate_subexp_standard): Use platform-specific integer
type instead of builtin_type_int8 as EVAL_SKIP return value type.
* ada-lang.c (ada_evaluate_subexp): Likewise.
* jv-lang.c (evaluate_subexp_java): Likewise.
* m2-lang.c (evaluate_subexp_modula2): Likewise.
* scm-lang.c (evaluate_exp): Likewise.
* value.h (value_bitstring): Add INDEX_TYPE argument.
* valops.c (value_bitstring): Add INDEX_TYPE argument, use it instead
of builtin_type_int32 as base range type.
* eval.c (evaluate_subexp_standard): Update value_bitstring call.