Weak symbols cannot use the small code model's usual ADRP sequences since the
instruction simply may not be able to encode a value of 0.
This redirects them to use the GOT, which hopefully linkers are able to cope
with even in the static relocation model.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205426 91177308-0d34-0410-b5e6-96231b3b80d8
