Sleep/Lenovo SL410 fails again after csup & clang

[Matt]

  My experience with a sleeping freebsd laptop has been shortlived!

Today I rebuilt world using clang & this morning's csup current.
Clang build went just swimmingly.

Unthinkingly, I closed my laptop lid and put it in my case.
When I got to my house, it was roasting with fans spinning and sleep 
light flashing. No damage, thankfully.

Low and behold, hw.pci.do_power_resume=0 no longer lets my laptop sleep!

I had recently fiddled with powerd, but problem persisted after 
reverting to previous configuration of associated sysctls etc.

Interestingly, sleep bounce now fails with a hard freeze, which it never 
has in the past.

Verbose output shows the wifi then re0 network interfaces going from 
D0->D3 as last living output.

Please note problem persists regardless of user, X running, sleep_delay 
sysctl, do_power_resume, do_power_nodriver, powerd running/not running.

Without sleep bounce, problem is characterized by flashing sleep light 
and spinning fans (CPU temperature is high).

No devices added or removed, was sleeping this morning before 
buildworld. Is it worth rebuilding with gcc? Or a content change and not 
a compiler issue? Any major pci changes lately maybe?

Matt
sendtomatt at gmail.com

Not sure where to go from here...
If it is helpful, I can provide any required logs, verbose dmesg etc.