gas/
* read.c (convert_to_bignum): New function, split out from...
(emit_expr): ...here. Handle the case where X_add_number is
positive and the input value is negative.
(output_big_sleb128): Fix setting of continuation bit. Check whether
the final byte needs to be sign-extended. Fix size-shrinking loop.
(emit_leb128_expr): When generating a signed leb128, see whether the
sign of an O_constant's X_add_number matches the sign of the input
value. Use a bignum if not.
gas/testsuite/
* gas/all/sleb128.[sd]: New test.
* gas/all/quad.[sd]: New test.
* gas/all/gas.exp: Run them.