It looks like usp10:usp10 is impacted too, but only for 64 bit builds, and only since the 18th instead of the 17th which is strange.
Still compiling with -O0 instead of -O2 seems to fix the new failures: * 329dfee70c35 -O2 usp10:usp10 test 1 to 10 failures on Vista-Win8 in test.winehq.org, 1 here https://testbot.winehq.org/JobDetails.pl?Key=21620
* 329dfee70c35 -O0 usp10:usp10 test 0 failures https://testbot.winehq.org/JobDetails.pl?Key=21621
* bd332f53f2d7 -O2 usp10:usp10 test 0 failures on Vista-Win8 in test.winehq.org, 1 here https://testbot.winehq.org/JobDetails.pl?Key=21622
* bd332f53f2d7 -O0 usp10:usp10 test 0 failures https://testbot.winehq.org/JobDetails.pl?Key=21623
The last victim is wininet:url but only on some Windows XP VMs. Again compiling the test with -O0 fixes the failures. https://test.winehq.org/data/tests/wininet:url.html
As far as I can tell these are the only tests that still have issues following the upgrade.