libqos: create libqos.c

libqos: create libqos.c

The intent of this file is to serve as a misc. utilities file to be
shared amongst tests that are utilizing libqos facilities.

In a later patch, migration test helpers will be added to libqos.c that
will allow simplified testing of migration cases where libqos is
"Just Enough OS" for migrations testing.

The addition of the AHCIQState structure will also allow us to eliminate
global variables inside of qtests to manage allocators and test instances
in a better, more functional way.

libqos.c:
        - Add qtest_boot
        - Add qtest_shutdown

libqos.h:
        - Create QOSState structure for allocator and QTestState.

ahci-test.c:
        - Move qtest_boot and qtest_shutdown to libqos.c/h
        - Create AHCIQState to interface with new qtest_boot/shutdown prototypes
        - Modify tests slightly to use new types.

For now, the new object file is only linked to ahci-test, because it still
relies on pc architecture specific code in libqos. The next two patches will
reorganize the code to be more general.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1421698563-6977-4-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>