Fix aux-target diagnostics for certain builtins

When I fixed the targets specific builtins to make sure that aux-targets
are checked, it seems I didn't consider cases where the builtins check
the target info for further info.  This patch bubbles the target-info
down to the individual checker functions to ensure that they validate
against the aux-target as well.

For non-aux-target invocations, this is an NFC.