Oracle bug #15826883 indicates that patch 119254-87 is the culprit in
my observed failure to apply 147440-25 to non-global zones. Oracle
knowledge base article ID 1504460.1 (Solaris 10 Patches May Fail to
Install in Non-global Zones) has their official word on this problem.
Anyone who installs patches in the order that they were released would
install 147440-25 *before* 119254-87 and not see the problem that I
got by installing 119254-87 first, and simply backing out 119254-87
should be sufficient for them. I have done this on hosts that have no
non-global zones.
The recovery process for my hosts that do have non-global zones is to
first patchrm 147440-25, then patchrm 119254-87, reboot (may not
strictly be necessary), patchadd 147440-25, and reboot again to make
147440-25 take effect. In this case it is important to remove
147440-25 before 119254-87 (the reverse order that they were
installed).
Both 119254-87 and 119255-87 have been withdrawn, so that should help
save everyone else from encountering this difficulty in the future.