Hotspot cross-compile broken in jdk8/build repo

[David Holmes]

After Kelly's push to jdk8/build a build-infra build is failing when 
cross-compiling hotspot. The symptom is the same as earlier this week: 
adlc is being compiled by the cross-compiler instead of the hostcc. But 
so far, as far as I can see, all of those fixes are in place.

It is probably going to take a file-by-file comparison to get to the 
bottom of it. I checked the main files and didn't see anything.

If I get time tonight I will check the generated files.

David