qapi: add QAPI visitor core

Base definitions/includes for Visiter interface used by generated
visiter/marshalling code.

Includes a GenericList type. Our lists require an embedded element.
Since these types are generated, if you want to use them in a different
type of data structure, there's no easy way to add another embedded
element. The solution is to have non-embedded lists and that what this is.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
diff --git a/Makefile.objs b/Makefile.objs
index 55d18bb..3b68f59 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -372,6 +372,12 @@
 
 libcacard-y = cac.o event.o vcard.o vreader.o vcard_emul_nss.o vcard_emul_type.o card_7816.o
 
+######################################################################
+# qapi
+
+qapi-nested-y = qapi-visit-core.o
+qapi-obj-y = $(addprefix qapi/, $(qapi-nested-y))
+
 vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
 
 vl.o: QEMU_CFLAGS+=$(SDL_CFLAGS)