open files on windows with FILE_SHARE_DELETE

[alfred-landrum]

Address the occasional rename related failures on Windows by using the FILE_SHARE_DELETE flag when opening files on Windows. As noted in #613, this unfortunately requires copying substantial code from the os package, as there's no way to use that flag with the existing os.Open api.

Fixes #613

[alfred-landrum]

I've created a Brim branch that uses this zq, and it shows many clean CI runs on Windows:
brimdata/zui#763

[henridf]

The zql/ os.Opens are still there, how about porting those over too?

[alfred-landrum]

The zql/ os.Opens are still there, how about porting those over too?

So zql/zql.go is a generated file from pigeon, which is why I had not updated it. I can make update the 2 use cases in zql_test.go, though.

[aswan]

A parser's OpenFile() method is boilerplate that pigeon creates but we never use that method...

[henridf]

So zql/zql.go is a generated file from pigeon, which is why I had not updated it. I can make update the 2 use cases in zql_test.go, though.

Ah, had missed that. My goal was simply to make it easy to grep -R os.Open and be sure there were none.