Assertion failure on if-then-else aliases

[AlviseDeFaveri]

Samples that trigger the bug:

out_nfs4_proc_get_root 0xffffffff813ed1d0
out_nfs4_server_capabilities 0xffffffff813ed120
out_dm_submit_bio_remap 0xffffffff81a424d0 
out_xs_udp_set_buffer_size 0xffffffff81cc1aa0 

The bug seems to be fixed if we add state splitting on stored values, as introduced by d954945, but this would trigger again the infinite loop reported in #13