[UBSan] Split nullptr-and-nonzero-offset-variable.cpp into C and C++ variants

I do not understand the BB failire, it fully passes locally.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@374306 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed