Deparse /$#a/ correctly

Deparse /$#a/ correctly

This is related to 4b58603b60.

This time it’s this op tree that pure_string can’t handle:

8     </> match() vK/RTIME ->9
7        <|> regcomp(other->8) sK/1 ->8
3           <1> regcreset sK/1 ->4
6              <1> av2arylen sK/1 ->7
5                 <1> rv2av[t2] sKR/1 ->6
4                    <#> gv[*a] s ->5

In writing a test for this, I triggered a case that 415d4c68d missed
(only $a and $b are exempt from strict vars, not @a and @b), so that
is fixed in the same commit.