[X86] Fix a few recursivelyDeleteUnusedNodes calls that were trying to delete...

[X86] Fix a few recursivelyDeleteUnusedNodes calls that were trying to delete nodes before their user was really gone.

We looked through a truncate to get to the load. So we should be
deleting the truncate first.

There is a check that the node is really unused before deleting
so this didn't cause a functional issue.