sizeof(void) etc. should be a hard error in C++.

PR16872.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188324 91177308-0d34-0410-b5e6-96231b3b80d8
Link in the ubsan runtime when building shared objects.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188325 91177308-0d34-0410-b5e6-96231b3b80d8