Don't use ArgFile when using JavaCompiler

[nosan]

Fixes build on Windows

see #44305

ArgFile should not be used when compiling sources via JavaCompiler.

[CreateProcess error=206, The filename or extension is too long]

This happens only when running a process via ProcessBuilder but not JavaCompiler.

[nosan]

My apologies, @snicoll.
I don't know how I overlooked this.

[philwebb]

Thanks @nosan, I was trying to look at this but it's taken me all day to get a Windows box installed!

[nosan]

I've installed VMware Fusion. Works perfectly :)

[snicoll]

There's no need for an apology @nosan. That's part of the review process and it's always tricky with limited access to a windows box. I like the toString() trick very much, good call 👍.