(HOST_WIDE_INT_MASK): Renamed from LONG_MASK; use HOST_WIDE_INT.

(HOST_WIDE_INT, HOST_BITS_PER_WIDE_INT): New (actually resuscitated) macros.
(parse_c_expression, expression_value, parse_escape, left_shift, right_shift,
struct constant, exp, parse_number, yylex): Replace `long' with
`HOST_WIDE_INT'.

From-SVN: r11061