[builtins][test] Don't XFAIL divtc3_test.c on 32-bit Solaris/sparc fo… (#72403)

As detailed in Issue #72398, the recent builtins rework and
77d75dc9 caused `Builtins-sparc-sunos::
divtc3_test.c` to `XPASS` on 32-bit Solaris/SPARC. Since there are
several underlying issues, un-`XFAIL` the test for now until those are
resolved, to turn the Solaris/sparcv9 buildbot green again after 5 days.

Tested on `sparcv9-sun-solaris2.11` and `x86_64-pc-linux-gnu`.