repoman: populate implicit IUSE for empty profile (bug 660982)

For the empty profile that's used to check dependencies of
ebuilds that have empty KEYWORDS, populate implicit IUSE
from all of the make.defaults files found in the relevant
repositories (this should take less than 1 second on most
hardware). Since the IUSE.missing check cannot be performed
without implicit IUSE settings, this makes the IUSE.missing
check work for ebuilds with empty KEYWORDS.

2 files changed