Revert "[CodeGen] Propagate dllexport to thunks"

This reverts r306770, it causes LNK4102 warnings in MSVC builds.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306835 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed