Changes to let cons handle bignums like general expressions.

	Changes to let cons handle bignums like general expressions.
	* expr.h (expressionS): New field X_unsigned.
	* expr.c (operand): Initialize X_unsigned to 1.  Set it to 0 for
	unary minus case.
	(expr) Fix typo resultP to right if missing operand.  Set
	X_unsigned to 1 when building new expression.
	* read.c (potable): Make "octa" and "quad" call cons, not
	big_cons.
	(cons): Handle bignums.  If given an O_constant (small integer) to
	fill a big space, turn it into a bignum.
	(parse_bitfield_cons): Set X_unsigned field.
	(bignum_low, bignum_limit, bignum_high, grow_bignum, big_cons):
	Removed.
	* read.h (big_cons): Remove prototype.
	* symbols.c (resolve_symbol_value): Don't give a warning if a
	symbol in expr_section can not be resolved.
	(S_SET_VALUE): Clear X_unsigned.
	* write.c (write_object_file): If resolve_symbol_value failed on a
	symbol we are writing out, give a warning.
	* config/tc-h8500.c (parse_reglist): Set X_unsigned.
	* config/tc-hppa.c (md_pseudo_table): Change "octa" and "quad" to
	call pa_cons, not pa_big_cons.
	(pa_big_cons): Remove.
	* config/tc-hppa.h (pa_big_cons): Remove declaration.
	* config/tc-i960.c (md_pseudo_table): Change "quad" to call cons,
	not big_cons.