We were already lazily linking functions, but all GlobalValues can be treated
uniformly for this.
The test updates are to ensure that a given GlobalValue is still linked in.
This fixes pr21494.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223681 91177308-0d34-0410-b5e6-96231b3b80d8
