ExecutionEngine: fix JIT/MCJIT selectTarget() duplication

This prepares for making JITCtor/MCJITCtor take a
TargetMachine* directly from clients like EngineBuilder.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131025 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed