[Sanitizer] Compile sanitizer runtimes with -Wno-non-virtual-dtor. Virtual dtors may be a problem for us, as sanitizer runtime should not generally assume libstdc++ presence.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@177860 91177308-0d34-0410-b5e6-96231b3b80d8