[OE-core] RDEPENDS_${PN} and virtclass-native

[Phil Blundell]

By way of displacement activity to avoid actually fixing my perl
compilation problem, it occurred to me to investigate why perl was
getting dragged into a micro-base-image build in the first place.  The
culprit turns out to be imake, which does:

RDEPENDS_${PN} = "perl xproto"

and is then BBCLASSEXTENDed to imake-native (which in turn is pulled in
by way of prelink-native and transfig-native).

Now, leaving aside the question of whether it is reasonable for prelink
to be depending on transfig, it is clearly wrong for the -native version
of imake to be depending on perl.  It seems that native.bbclass makes
some effort to rewrite plain RDEPENDS to the -native version, but it
doesn't apply the same tactics to RDEPENDS_${PN} or any such.  (And, in
fact, rewriting plain RDEPENDS is probably futile since few if any
recipes are going to be setting it.)

Obviously I can fix this by just setting RDEPENDS_virtclass-native in
the recipe, and that's what I've done in my local tree.  But I wonder if
a better solution would be for native.bbclass to be slightly more
adventurous about rewriting these things for itself.

p.