Fix .cmd scripts help arguments

[safern]

In windows if we call any of the subset helper scripts, coreclr.cmd, libraries.cmd or installer.cmd with -h, -help or -? we get arcade's help which is miss leading in some arguments like, -arch is shown as -platform. The reason for that is because subset scripts pass -subsetCategory <subset> as the first argument when calling build.cmd and in build.cmd, in order to print help, we check for %~1.

Also without this change, it doesn't match Unix behavior, as if we call coreclr.sh-h then we get the expected output of our eng\build usage output.

[ViktorHofer]

That won't work with /? (or -?) which was the reason why we introduced the helper checks in the cmd file.

[safern]

That won't work with /? (or -?)

It actually works with /?, the only one that didn't work is -?... I just added support for it in the .cmd scripts.

[safern]

@jkoritzinsky @ViktorHofer could you please review again whenever you have time?

[safern]

Thanks @jkoritzinsky.

will go ahead and merge since @ViktorHofer is OOF already. Viktor let me know if you have any concerns and I will address them as a follow up PR.

[ViktorHofer]

Are we still dot sourcing this script anywhere? If not, we can remove the if block.

[safern]

Hmmm I'm not sure about that. I don't think so. Would searching for -Command be enough?

[ViktorHofer]

I'm relatively sure that this is dead code and you can just remove it.

[safern]

Ok. Will remove it then.

[ViktorHofer]

thanks