extraFlagsArray should not be exposed outside of `makeWrapper`, it
should only be possible to set it inside a script supplied via the
`--run` argument.
The tests need to expand passed variable and very carefully.
I could see no other easy way than to change single-quoting in
makeWrapper to double-quoting.
The tests now fail with the same problem as on master...
By default `makeWrapper` will not set argv[0] (this is a reversion to
the old default behavior). Based on the breakage we have seen from
changing the default, this is what most people want. The `wrapProgram`
function will send `--argv0 '"$0"'` to `makeWrapper`, i.e. it will
continue to pass-through the argv[0] that the wrapper is called with.
