Build all executables by default except for the known-broken ones.

This also allows running qemu-iotests without manually building
socket_scm_helper.

Reported-by: Max Reitz <mreitz@redhat.com>
Tested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Add vertex shader which flips the texture upside down while blitting it.
Add argument to qemu_gl_run_texture_blit() to enable flipping.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20171010135453.6704-4-kraxel@redhat.com

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>