Revert GCC -Wnon-virtual-dtor workarounds "[SCEV] Fix GCC -Wnon-virtual-dtor" & "[SampleFDO] Fix -Wnon-virtual-dtor" This reverts commits 4852c770 and 6df09d6c. After D109404, -Wnon-virtual-dtor will not be added when the host compiler is GCC.