`stubs/igvm.c` includes `igvm-internal.h`, that in turn includes the igvm library.
This is required just for the QIgvm declaration and creates an
unnecessary dependency on the library.
Since igvm is not listed as a dependency of stubs, this results in build
failing when the library is not installed in a "well known" path of the
system.
Add a forward declaration for QIgvm and move the definition of
`qigvm_directive_madt` to `igvm.h` so that we can drop `igvm-internal.h` from
`stubs/igvm.c`.
Fixes: dea1f68a5c ("igvm: Fill MADT IGVM parameter field on x86_64")
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Luigi Leonardi <leonardi@redhat.com>
Message-ID: <20260309-master-v2-1-7e02f07a1096@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
5c45204e34