Revert "Remove access to the DataLayout in the TargetMachine"

This reverts commit 0f720d984f419c747709462f7476dff962c0bc41.

It breaks clang too badly, I need to prepare a proper patch for clang
first.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243089 91177308-0d34-0410-b5e6-96231b3b80d8
17 files changed