MFC r330086, r333155: seq(1) improvements

MFC r330086 (cem): seq(1): Consistently include 'last' for non-integers

The source of error is a rounded increment being too large and thus the loop
steps slightly past 'last'. Perform a final comparison using the formatted
string values (truncated precision) to determine if we still need to print
the 'last' value.

MFC r333155: seq(1): Move long_opts up with globals

PR: 217149