do not warn when optimizing away /x{0,0}?+/ and /x{0,0}+/

In c37d14f947f7998211b0455e453160fb7e15b22e Karl fixed an issue
reported in [perl #118375] "5.18 regex regression Quantifier follows nothing in regex"
but he fixed only the non-greedy modifier mentioned in the ticket,
and did not include support for the other quantifier modifiers like the
non-greedy possessive (stupid but not illegal), and the possessive
(useful) modifiers.

Hopefully this covers them all.

Note that because Karl already included support for m/x {0,0} ?/x
I have done so as well for the new cases. I do not necessarily endorse
the idea that it is legal or should be tested for. I am inclined to
think that '{0,0}?+' should be indivisible even under /x.