Add target analysis passes to the codegen pipeline for MCJIT.

This patch adds the target analysis passes (usually TargetTransformInfo) to the
codgen pipeline. We also expose now the AddAnalysisPasses method through the C
API, because the optimizer passes would also benefit from better target-specific
cost models.

Reviewed by Andrew Kaylor

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199926 91177308-0d34-0410-b5e6-96231b3b80d8