bigint variants). Clean up some inconsistencies in error message wording.
Fix scanint8 to allow trailing whitespace in INT64_MIN case. Update
int8-exp-three-digits.out, which seems to have been ignored by the last
couple of people to modify the int8 regression test, and remove
int8-exp-three-digits-win32.out which is thereby exposed as redundant.
truncating to integer. Remove regress test that checks whether
4567890123456789 can be converted to float without loss; since that's
52 bits, it's on the hairy edge of failing with IEEE float8s, and indeed
rint seems to give platform-dependent results for it.