llc.cpp also defined these flags, meaning that when I linked all of LLVM's
libraries into a single shared library, llc crashed on startup with duplicate
flag definitions. This patch passes them through the EngineBuilder into
JIT::selectTarget().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95390 91177308-0d34-0410-b5e6-96231b3b80d8