Revert "Move metadata linking after lazy global materialization/linking."

This reverts commit r251926. I believe this is causing an LTO
bootstrapping bot failure
(http://lab.llvm.org:8080/green/job/llvm-stage2-cmake-RgLTO_build/3669/).

Haven't been able to repro it yet, but after looking at the metadata I
am pretty sure I know what is going on.

llvm-svn: 251965