Initialize WOW64 in TouchFile custom action

[robmen]

Fixes wixtoolset/issues#8638

[robmen]

WcaInitializeWow64() was a bit new to me, so I'm not sure this is the best way to use it. It felt like a real hassle given the way this code is structured so I'm open to suggestions if I misunderstood how WcaInitializeWow64() and friends were intended to be used.

[barnson]

I'm actually curious why this is needed. A 32-bit package can't touch the 64-bit file system so this would only be useful for touching a file installed by somebody else, no?

[robmen]

Yes. Touching a file outside of the MSI package.

Note: I've not run the test, so this could fail there. This was something simple I could throw together while recovering.