Re-order some flag bits to avoid potential branches

Re-order some flag bits to avoid potential branches

The ANYOF_INVERT flag is used in every single pattern match of
[bracketed character classes].  With backtracking, this can be a huge
number.  All the other flags' uses pale by comparison.  I noticed that
by making it the lowest bit, we don't have to use CBOOL, as the only
possibilities are 0 and 1.  cBOOL hopefully will be optimized away, but
not always.  This commit reorders some of the flag bits to make this one
the lowest, and adds a compile check to make sure it isn't inadvertently
changed.