Revert "ThinLTO: do not import function whose linkage prevents inlining."

This reverts commit r268315, the tests are not passing.

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268317 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed